EP3283814A1

EP3283814A1 - Illumination unit comprising leds

Info

Publication number: EP3283814A1
Application number: EP16705919.5A
Authority: EP
Inventors: Philipp SCHLOSSER
Original assignee: Osram GmbH
Current assignee: Osram GmbH
Priority date: 2015-04-15
Filing date: 2016-02-17
Publication date: 2018-02-21
Also published as: US20180094781A1; CN107466351A; WO2016165856A1; DE102015206801A1

Abstract

The present invention relates to an illumination unit (2) comprising a planar substrate (7) and LEDs (8) thereon, wherein each of a plurality of portions (7a) of the substrate (7) is partially separated from the remaining substrate (7b) by means of an open joint gap (23), so each of the portions (7a) is still connected to the remaining substrate (7b) via a bridge region (24), on each of which portions (7a) at least one of the LEDs (8) is mounted and each of which portions (7a) is further folded out from the remaining substrate (7b) at the bridge region (24) and so positioned obliquely thereto.

Description

description

Lighting device with LEDs Technical area

The present invention relates to a

Lighting device with a flat substrate and a plurality of LEDs on it.

State of the art

The advantages that LED-based compared to conventional light sources, for example. Have energy efficiency, are known. A challenge may arise with respect to the relative arrangement, ie, in concrete terms, the mounting of the LEDs, for example, to produce a desired light distribution in the far field or else a special, typically as homogeneous as possible illumination intensity distribution on a radiating surface.

Presentation of the invention

The present invention is based on the technical problem, a particularly advantageous

Indicate lighting device and a method for their preparation.

According to the invention, this object solves a

A lighting device for emitting light, comprising a sheet substrate, a printed circuit pattern on the substrate, a plurality of LEDs mounted on the substrate mounted and electrically conductive with the

Conductor track structure are connected, wherein a plurality of subregions of the substrate of the remaining substrate with one of the substrate in the thickness direction passing, but in their longitudinal extension but open parting line are partially separated, so are each still connected via a bridge area with the rest of the substrate, which joints each spaced from one edge of the substrate with respect to its surface directions extend completely within the substrate, and wherein in the sub-regions in each case at least one of the LEDs is arranged and which portions are further folded respectively around the bridge area from the rest of the substrate and so obliquely employed; and a method comprising the steps of: providing the substrate; Introduction of the joints;

Folding out the subregions from the remaining substrate.

Preferred embodiments are to be found in the dependent claims and the entire disclosure, wherein the presentation does not always distinguish in detail between device and method or use aspects; In any case, implicitly, the disclosure must be read with regard to all categories of claims. A basic idea of the invention is thus to provide a flat, ie thin substrate, but nevertheless to achieve an at least partially detached from the surface adaptability of the light output (with respect to the directions) by folding out the subregions. Compared to an already three-dimensional substrate body, such as an injection molded part, so for example, the manufacturing cost can be reduced. The substrate can be equipped with the LEDs approximately before folding out the subregions, that is, in principle, two-dimensionally, which can be easier to integrate into a mass production than equipping a three-dimensional object. The "planar" substrate has in each of its surface directions a considerably larger, for example, by at least 20, 50, 100, 250, 500 or 1,000 times (in the order of naming increasingly preferred), extension as In the case of a thickness varying across the substrate, an average value formed over the substrate is considered, and preferably the thickness is constant.

The subregions are each partially separated with a parting line from the rest of the substrate. The "remaining substrate" is the substrate apart from all subareas, so there is no subregion to it, but this separation is only conceptual in nature, each of the subregions is connected to the rest of the substrate via the respective bridge region, which is also part of the substrate. The substrate is at least in relation on the surface directions, preferably in the whole, a monolithic part of it, apart from statistically randomly arranged inclusions therein, such as reflection particles, in its interior is free of material boundaries between different materials or materials of different production history. In other words, the partial regions, the remaining substrate and the bridge regions are made of the same, continuous substrate material. The folded out of the rest of the substrate portions are separated from it with the respective parting line (only) partially, because the joints in their longitudinal extension each describe open (not closed) curves; Preferably, the joints are each U-shaped. In any case, the joints are each completely within the substrate, so do not reach to an outer edge of the substrate (but are just spaced with respect to the surface directions of the substrate). In other words, the parting lines (with respect to the surface directions) each extend between two end points and in each case both end points lie within the planar substrate. This may, for example, be advantageous insofar as an edge region of the substrate can remain free of joints, which can increase the mechanical stability. By placing the partial regions in the surface, it is also possible to realize very large-area substrates with a large number of obliquely applied partial regions / LEDs on the basis of a single substrate. The illumination device according to the invention has a "plurality" of LEDs, for example in this order increasingly preferably at least 5, 10, 20, 30, 40, 50, 60, 70, 80, 90 or 100 LEDs, possible upper limits can (independently thereof), for example With the lighting device and a corresponding number of LEDs, for example, a large-area light output can be realized, with the folded out partial areas, as explained in more detail below, for example, a uniform

Illuminance distribution on the exit side can be achieved.

In the subregions, at least one of the LEDs should be provided in each case and, for example, not more than 5, 4, 3 or 2 LEDs (increasingly preferred in the order in which they are mentioned); Particularly preferably, exactly one LED is arranged in each subarea. "LED" preferably means an LED chip which is enclosed in its own form. As "plurality" of subareas, for example, at least 5 subareas (and independently thereof) may be used, for example. B. be provided not more than 1,000 sub-areas; The lower and upper limits disclosed above for the number of LEDs in the lighting device may also be preferred in the case of the subregions (also irrespective of how many LEDs are provided per subregion).

Together with the LEDs and other components may be disposed on the substrate, such as a driver ^¬ and / or control electronics, or resistors, connectors or more of the contacting / operation of the LEDs serving components. Of course, in addition to the LEDs which are arranged in accordance with the invention in the subregions, it is generally also possible to provide further LEDs on the substrate. Preferably, however, all the LEDs of the lighting device are arranged in folded out partial areas, which are each formed with a parting line. In general, the subregions, for example, each have an area of at least 10 mm ² , 30 mm ² or 50 mm ² and independently thereof of not more than 5,000 mm ² , 3,000 mm ² , 1,000 mm ² or 500 mm ² (in each case in FIG the order of naming increasingly preferred).

The subregions are folded out of the rest of the substrate around the respective bridge region, ie bent out of the rest of the substrate as a kind of hinge, for example, in each case in order more preferably at least 10 °, 15 °, 20 °, 25 °, 30 ° , 35 ° and 40 ° and (independently) by not more than in this order increasingly preferably at most 80 °, 70 °, 60 ° and 50 °, respectively. The three-dimensional arrangement created by bending out remains due to plastic deformation of the substrate itself and / or a part connected thereto (preferably the track structure, see below). Preferably, the subregions are each folded out of the remaining substrate around a fold line, thus in each case a fold line marks the transition between the subregion and the remaining substrate. For each subregion, the respective fold line then preferably extends as straight connecting line between the two end points of the associated parting line. Preferably, the rest of the substrate is flat for itself and / or the subregions are each plan by itself, particularly preferably both. The remainder of the substrate is considered to be "self-leveling" if a region thereof within which the subregions are located is planar, so that the remaining substrate can be bent over in an edge region for assembly purposes, for example for example, to a surface portion of at least 70%, 80% or 90% plan.

In a preferred embodiment, the remaining substrate on the substrate has an area fraction of at least 30%, wherein at least 40%, 50% or 60% are further, in the order of naming increasingly preferred lower limits. On the other hand, the surface area of the rest of the substrate should amount to, for example, not more than 90% or 80%.

If reference is made to a "planar" configuration of the remaining substrate (s), this means that the side surfaces opposite each other in the thickness direction lie in one plane in the corresponding region (the respective subregion / remaining substrate) Planes are parallel to each other (the planes have a distance corresponding to the thickness of the substrate) .The surface and thickness direction of the substrate are always considered locally, so then, for example, together with a respective sub-area inclined to the rest of the substrate.

The folded-out or "obliquely" employment of a respective partial area relative to the rest of the substrate means, for example, that the thickness direction in the respective partial area to that in the remaining substrate is increasingly preferably at least 10 °, 15 °, 20 °, 25 °, 30 ° in this order °, 35 ° or 40 ° tilted upper limits independent of these lower limits may, for example, in this order increasingly preferably at most 80 °, 70 °, 60 ° or 50 °.

Due to the "oblique" position of a respective partial area relative to the remaining substrate, for example, the main propagation direction of the light emitted from the respective partial area relative to the thickness direction of the remaining substrate may be increased in this order increasingly preferably at least 10 °, 15 °, 20 °, 25 °, 30 °, 35 ° or 40 ° tilted, possible upper limits are (independent of the lower limits), for example, in this order increasingly preferably at most 80 °, 70 °, 60 ° or 50 °

In this case, the "main propagation direction" is formed in each case as the mean value of all the direction vectors along which light is emitted by the LED (s), wherein in this averaging each direction vector is weighted with its associated light intensity.

In this case, the thickness direction of the remaining substrate is initially taken directly per subarea at the parting line of the respective subarea in the remaining substrate, if necessary, as formed along the parting line average. In the preferred case of the remaining planar substrate, the thickness direction of the planar part thereof is taken as the basis. Although the subregions are therefore preferably planar in each case, in general they can also have a more complex structure, for example, in each case being subdivided into a plurality of subareas. For each subarea, for example, the next adjacent subareas can then be tilted relative to each other, but in each case be flat. Of course, it is also possible, for example, to combine only a partially planar surface on which the LED (s) are seated / sitting with subplanes which are not planed for themselves (per subarea). In a preferred embodiment, the substrate is made of a plastic material, such as a

Polyester material, preferably made of

Polyethylene terephthalate (PET). The substrate is preferably single-layered (monolithic with respect to the thickness direction), so it is, for example, a simple plastic sheet.

In general, for example, the substrate could also be made of a metal, for example aluminum or an aluminum alloy. An insulation layer, such as an imide layer, would then be arranged between the substrate and the conductor track structure. Regardless of whether the interconnect structure and the substrate directly adjoin one another (which is preferred) or in between a layer or a layer system is arranged, form the Substrate and the interconnect structure a one-piece part, so they can not be non-destructively separated (without destroying part of the composite) from each other. In a preferred embodiment, the substrate is disposed on a support having a higher flexural rigidity. The bending stiffness of the carrier should, for example, be at least 2, 4, 6, 8 or 10 times that of the substrate. In principle, a rigid support may also be provided, although preferred upper limits are, for example, at most 1,000, 500 or 100 times the flexural rigidity of the substrate. The carrier can be provided, for example, of a metal or preferably a plastic material, particularly preferably of PET. The higher bending stiffness can, for example, also be achieved by a greater thickness compared to the substrate.

Although in general, for example, a grid as a carrier is conceivable, with respect to its surface directions continuously (uninterrupted) trained flat carrier is preferred, such as a plate. Its perpendicular to the surface directions generally taken as an average, preferably constant, thickness may, for example, at least 0.5 mm, preferably at least 1 mm, more preferably at least 1.5 mm, more preferably at least 2 mm, be possible, with possible upper limits (thereof independently), for example, at most 5 mm, 4 mm or 3 mm (in the order of naming increasingly preferred). Furthermore, the should Flatness of the substrate numbers also for the carrier (its extension from outer edge to outer edge) to be disclosed. The carrier connects in the thickness direction of the remaining substrate, this and the carrier extend parallel to each other. The carrier should, for example, extend over at least 60%, 70%, 80% or 90% of the area of the remaining substrate on the remaining substrate. The carrier is preferably a part of the whole plan. The substrate and the carrier are integrally separable with each other, that is, non-destructively (without destruction of either or both of the layers). Preferably, the carrier and the substrate are set as previously separate parts together and connected to one another with a material-bonding joint connection, preferably an adhesive compound, particularly preferably a large-area adhesive film. The assembly of substrate and carrier can, for example, in a tape or reel process (reel-to-reel) take place. By folding out the subregions from the remaining substrate, the latter is interrupted where the subregions are folded out. The support may also be interrupted in the remaining substrate in the region of these interruptions (with respect to its thickness direction), partially or preferably completely congruent with the interruptions in the remaining substrate. This may be of interest, for example, in the case of a lighting device which is to emit light on both sides of the substrate, ie approximately in the case of Trap of a luminaire intended to illuminate both wall and / or ceiling and the room in front of it.

In a preferred embodiment, a planar reflector is provided on the substrate (see the above disclosure on the "flatness" of the substrate and support); the reflector and the substrate are integral with one another, ie, non-destructively separable (see the above disclosure of the support In general, the reflector can also be applied as a reflection layer, that is to say as a layer which is formed / emerged only when it is applied and insofar as it was not a separate part, but preferably the reflector and the substrate are placed against one another as previously separate parts cohesive joint connection held together, particularly preferably an adhesive bond, in particular a large-area adhesive film (see the above disclosure to support and substrate).

The reflector is made of a material with a reflectance of at least 60%, in this order increasingly preferably at least 65%, 70%, 75%, 80, 85%, 90%, 95%, 97% and 98%, respectively; although the highest possible degree of reflection may be preferred, an upper limit can for example be 99.9% for technical reasons (considered in each case an average formed over the visible spectral range from 380 μm to 780 μm). In general, the reflector could also be made of metal, but is preferably a reflector made of a plastic material and is the Reflectivity more preferably adjusted by embedded therein inclusions, such as embedded gas bubbles or preferably reflection particles, eg. B. titanium dioxide particles. The reflector is preferably a plastic sheet.

In a preferred embodiment, the carrier and reflector are the same part, which is thus characterized at the same time by the bending stiffness and the reflection properties. It must then, for example, fewer items are assembled.

Preferably, the reflector is arranged on a front side of the substrate on which the LEDs of the subregions are mounted. The partial regions can then preferably be folded out to a rear side opposite this front side, ie the light from the LEDs is indeed emitted at the front side of the substrate, but then reflected and emitted by the illumination device as a whole at the rear side of the substrate, cf. Fig. 1 for illustration. This indirectly emitted light can, for example, already produce a comparatively homogenous illumination intensity distribution on a downstream diffusing screen of a luminaire, which, for example, permits a smaller distance between the illuminating device and the diffusing screen and thus a compact construction (compare FIG. 4 for illustration). On the other hand, the scattering coefficient of the lens can be reduced, namely, the lens must to produce a homogeneous

Illuminance distribution on its exit side scatter less if already the

Illuminance is more homogeneous on its entrance side. This can increase the efficiency.

In a preferred embodiment, the subareas are thus folded out to one of the front side (see the following definition) opposite back of the substrate. The subregions are thus folded into a rear space, which rear space faces the rear side of the substrate (and faces away from the front side).

In a further embodiment of the folded out to the rear portions, the reflector provided on the front extends over the

Interruptions in the rest of the substrate across (see the front), preferably in turn uninterrupted. The light of the LEDs thus falls on a side facing the substrate of the reflector and is discharged into the above-mentioned rear space after reflection. With this construction, the proportion of light emitted indirectly can be maximized; it can be, for example, at least 70%, 80% or 90% (increasingly preferred in the order in which they are mentioned), more preferably the lighting device emits exclusively indirect light So be called "glare-free".

The "front side" is that side of the substrate on which the LEDs of the subregions in question are arranged, which subregions are each equipped on one side, that is, one side per subarea free of LEDs; Further, the LEDs of the portions are mounted on the same side of the substrate, which is just referred to as the front. In general, in addition to LEDs can also be mounted on the back of the substrate, preferably, however, the back of the substrate is free of LEDs, the substrate is in the whole so only one-sided equipped.

This can be advantageous, for example, insofar as a layer system comprising the substrate can already be made simpler and thus more cost-effective; for example, interconnects are also required only on one side of the substrate. Furthermore, the one-sided assembly can be simplified compared to a two-sided assembly. Preferably then all subregions of the lighting device are folded out to the same side.

In another preferred embodiment (previously described in the context of indirect light output), the subregions are flipped out to the front of the substrate. The subregions are thus folded into a front space, which faces the front side of the substrate. A certain homogenization of the illuminance distribution on the inlet side of the

Diffuser can be achieved even if only part of the light incident thereon is indirect light.

For this purpose, the sub-area just eg. Folded out to the front and the reflector can be arranged on this front. In this case, the light is emitted Overall, at the front of the substrate, so the lens of the (partially covered with the reflector) front of the substrate is facing. A mixture of light emitted directly by the LEDs (reflectance-free) and light reflected by the reflector then falls on the diffuser, and the ratio can also be set by how inclined the subregions are (the more obliquely the more light is reflected). In a preferred embodiment, the substrate has a thickness of at least 150 ym, preferably at least 200 ym, more preferably at least 250 ym. Advantageous upper limits may be, for example, at most 500 ym, preferably at most 450 ym, more preferably at most 400 ym, particularly preferably at most 350 ym, wherein the upper and lower limits may be expressly also independently of interest. For example, in the case of the preferred plastic material, for example the PET, the inventor has found in the stated range, on the one hand, a good basic stability of the substrate, but on the other hand, the partial regions can also be folded out well.

In a preferred embodiment, which may also be of interest regardless of a concretisation of the substrate thickness, the conductor tracks have a thickness of at least 20 μm, preferably at least 25 μm, more preferably at least 30 μm, particularly preferably at least 35 μm. Advantageous upper limits can, for example, at most 100 ym, preferably at most 90 ym, more preferably at most 80 ym, more preferably at most 70 ym, wherein the upper and lower limits may in turn be independently of interest. For the wiring pattern, a copper material is preferable. The copper may, for example, be laminated or be so that, for example, a copper foil is adhesively bonded to the substrate via an adhesive layer. Preference is given to an electrolessly deposited in a bath on the substrate copper. In this case, for example, in a first step, first part of the layer (seed layer) can be deposited and patterned or even deposited onto a mask, and then in a second deposition step the seed layer is reinforced to form the conductor track structure. But it is also a one-step deposition possible.

The thickness of the substrate / trace structure is taken along the thickness direction (s) of the substrate, and in the case of a nonuniform thickness across the substrate, a mean value formed above it is considered. In each case a constant thickness is preferred.

The invention also relates to a luminaire with a lighting device disclosed herein and a diffusing screen. The illumination device and the lens are arranged relative to one another such that at least a portion of the light emitted by the illumination device falls onto the lens, for example at least 30%, preferably at least 40%, of the light. Because the Lighting device generally also be designed to emit light on both sides of the substrate, not necessarily all the light must be passed over the lens, it can, for example. At the same time a wall / ceiling and the diffuser the room in front of it be illuminated (see the front). It can also be provided a second lens, so that is then arranged on both sides of the substrate in each case a lens. In the example just mentioned, the space would then be illuminated via the first diffuser and would be illuminated via the second diffuser wall / ceiling.

However, if all the light is emitted on one side of the substrate, a correspondingly larger part of the light preferably falls on the lens, for example at least 80% or 90%. However, for technical reasons, upper limits can be 99% or 95%, for example. The diffuser is preferably designed as a plane-parallel plate, at least in the area which passes through the light emitted by the lighting device. The scattering of the scattering disk can be adjusted, for example, by means of scattering centers embedded in the scattering disk material, for example scattering particles, and / or surface scattering centers at the entry and / or exit side of the scattering disk. The surface scattering centers can be realized, for example, by roughening the surface or by applying a scattering coating.

As already mentioned at the outset, the invention also relates to a production method. The above execution too the lighting device or luminaire should be expressly disclosed in this regard.

In a preferred embodiment, the joints are introduced with a mechanical cutting tool or by laser cutting. As mechanical

Cutting tool is a punching tool preferred, it is then the parting lines stamped, which, for example, in a reel-to-reel process is possible. In general, however, the joints could, for example, also be etched; On the other hand, however, punching can offer advantages in terms of throughput and thus in particular in a mass production, whereas laser cutting allows a high degree of flexibility.

It is also clear from these different examples that the joints can also have a very different width depending on the production. The width of a parting line is in each case taken perpendicular to its longitudinal extension, in a respective surface direction of the substrate, and indeed in the case of a width varying over the length extent as an average formed above. In this case, the substrate is considered with not yet folded out partial areas, so in the case of the finished lighting device, a situation as if the sections were not yet unfolded (or mentally collapsed again).

For example, in the case of introduced with a cutting tool parting line, this can also be arbitrarily small, so the sub-area and the rest of the substrate along the Even adjoin parting line. When laser cutting, however, there will be a certain minimum width, such as 50 ym, 100 ym and 150 ym. Even with a cutting tool, however, can be introduced a wider dividing joint, for example, with two in their distance from each other, the width of the parting line predetermining, extending parallel cutting. It is generally preferred that the width of the parting line is not greater than 500 μm, 400 μm, 300 μm or 200 μm. In a preferred embodiment, the conductor track structure is plastically deformed locally during the folding out of the subregions, that is to say that the conductor track structure then at least partially stabilizes the folded-out position. The conductor track structure would therefore have to be plastically deformed again in order to fold back the subregions. In particular, in connection with this stabilization function, the above-mentioned thicknesses have proved to be advantageous. The "local" deformation takes place, for example, in each case where a respective fold line in the substrate with the

Track structure cuts.

It may also be preferred that in view of such a stabilization of the subregions, in each case where the respective fold line runs, in addition to the conductor track structure, a stabilization metallization which is not electrically conductively connected thereto but is preferably applied in the same process as the conductor track structure is provided. So such not contributing to the power supply Stabilization metallization can, for example, cover the respective fold lines as extensively as possible and, as just described for the printed conductor structure, deform plastically there when folding out the partial areas. In a preferred embodiment, the LEDs are already mounted on the substrate when folding out the subregions, ie the LEDs are first mounted and then the subregions folded out. This can considerably simplify the mounting of the LEDs. Preferably, the LEDs are already mounted on the substrate during insertion of the parting lines.

As explained in detail above, a preferred lighting device comprises a support and / or a reflector, preferably the two as an integrated part. The assembly then takes place in a preferred embodiment such that first the subregions folded out of the substrate and then the substrate and the carrier / reflector are assembled. When assembling the carrier / reflector with the substrate so the sub-areas are already folded out of the latter.

Brief description of the drawings

In the following, the invention will be explained in more detail with reference to an embodiment, wherein the individual features in the context of the independent claims in another combination may be essential to the invention and continue to distinguish between the different categories of entitlements.

In detail shows

Fig. 1 is a lamp with an inventive

Lighting device therein;

Figures 2a-f show various steps in the manufacture of a lighting device according to the invention;

3 shows a lighting device according to the invention in an oblique view;

Fig. 4 is a schematic diagram for illustrating the invention with a

Illumination device on the diffuser of the luminaire according to FIG. 1 achievable homogenization of the illumination intensity distribution.

Preferred embodiment of the invention

Fig. 1 shows a lamp 1 with a lighting device 2 according to the invention, which is arranged in a housing 3 of the lamp 1. The light output is in the figure up, and the lighting device 2 downstream is a diffuser 4 of the lamp 1 is provided. The light emitted by the lighting device 2 falls on an entrance side 5 of the lens 4, is scattered on scattering particles embedded in the lens material (not shown) and with a correspondingly more homogeneous Illuminance distribution at an exit side 6 of the lens 4 issued.

With the illumination device 2 according to the invention explained in detail below, a fairly homogeneous illumination intensity distribution can already be achieved on the inlet side 5 of the diffusing screen 4, which is why a diffuser of lower scattering can be provided for the light 1, which improves the efficiency. On the other hand, for example, the distance between lens 4 and lighting device 2 can be reduced, which may allow the construction of particularly flat lamps 1, in the lamp 1 is preferably a recessed light. The lighting device 2 according to the invention is constructed from a substrate 7, from which a plurality of partial regions 7a are folded out. As the substrate 7, a plastic sheet of PET having a thickness of 300 μm is provided. The partial regions 7a are partially separated from the remaining substrate 7b via a parting line, cf. in particular also Fig. 2d for illustration. In each of the subregions 7a, an LED 8 is mounted in each case, the LEDs 8 are therefore each folded out together with their respective portion 7a from the rest of the substrate 7b and so obliquely employed.

The LEDs 8 are mounted on a front side 9 of the substrate 7. The partial regions 7a are each at a rear side 10 opposite this front side 9 popped up. The LEDs 8 each emit the light approximately lambert, with a respective, as a mean value per LED 8 formed Hauptausbreitungsrichtung 11 obliquely downwards (approximately at 45 ° to the vertical).

Of the LEDs 8 so only a small portion of the light passes directly, so reflection-free, on the lens 4. The greater part of the light is previously reflected, to a reflector 12 and the substrate 7 itself. Also, the reflector 12 is a PET plastic sheet which, however, is thicker than the substrate 7 with a thickness of 600 μm. Due to the greater thickness of the reflector 12 has a greater bending stiffness compared to the substrate 7. The reflector 12 thus serves at the same time a mechanical stabilization of the substrate 7, that is, at the same time also a carrier.

Where the subregions 7a are folded out of the remaining substrate 7b, the latter is interrupted. The reflector / carrier 12 is formed continuously in the region of these interruptions 13, so extends over the interruptions 13 away.

Since the light emitted by the LEDs 8 now only partially free of reflection reaches the lens 4, but for the most part is previously reflected, each of the LEDs 8, a larger area of the lens 4 is illuminated. These areas overlap, resulting in a result in a relatively uniform illumination intensity distribution on the inlet side 5 of the lens 4, cf. see also Fig. 4 in detail. In FIG. 1, for clarity, one of the electrical contacting of the LEDs 8 serving conductor track structure is not shown. These

Printed wiring pattern is deposited on the front side 9 of the substrate 7 (before assembling the substrate 7 and the reflector 12). In the finished illumination device 2, it then extends in sections between the substrate 7 and the reflector 12 and in the subregions 7a on the side of the subregions 7a facing the reflector 12.

The luminaire 1 further has a drive electronics 14 arranged in the housing 3 together with the lighting device 2, which is electrically conductively connected to the printed conductor structure arranged on the substrate 7. Via external power supply lines (not shown), the driver electronics 14 is connected to a mains connection, it then adapts the mains voltage for operation of the LEDs 8. A driver electronics, such as a ballast, but can also be arranged outside of the lamp 1, which may optionally allow a more compact design. Furthermore, this may also be advantageous, for example, if light is to be emitted with the luminaire 1 on both sides of the substrate 7 (both into the room and to the wall / ceiling).

The production of the lighting device 2 according to the invention will be explained in more detail below with reference to FIG. 2. In a first step (FIG. 2 a), a copper layer 21 is applied to the substrate 7, that is to say de-energized in a bath. Alternatively, for example, a substrate with a laminated on, so glued copper layer could be used. From the copper layer 21, the conductor track structure 22 is then worked out (FIG. 2 b), for which purpose the copper layer 21 is masked with a photoresist. This is exposed and opened locally, so that in a subsequent etching process, the areas are exposed, which then lie between the tracks 22. After the etching, therefore, the conductor track structure 22 remains (and the photoresist is removed).

The LED 8 is then mounted on the printed conductor structure 22 in a next step (FIG. 2 c), specifically as a so-called SMD component [Surface Mounted Device]. The LED 8 thus has two rear side contacts (not shown) facing the interconnect structure 22 and the underlying substrate 7, which are connected to the interconnect structure 22 via a cohesive joint connection layer, either via an electrically conductive adhesive (eg filled with silver). or a low-temperature solder.

Next, for each subarea 7a, a parting line 23 which partially separates the respective subarea 7a from the remaining substrate 7b is structured, which extends as a non-closed, U-shaped curve (FIG. 2d). however, each of the partial regions 7a remains connected to the remaining substrate 7b via a bridge region 24. The joints 13 are either by laser cutting, which allows high flexibility, or introduced by punching, which can enable a good throughput.

The partial regions 7a are then folded out of the remaining substrate 7b around the bridge region 24 as a hinge, in each case at an angle of approximately 45 °. In the bridge regions 24, a fold line then extends, which marks the transition between partial region 7a and remaining substrate 7b.

In a last step, the reflector 12 is assembled with the substrate 7, for which purpose the front side 9 of the substrate 7 in the region of the remaining substrate 7b is coated with an adhesive film and substrate 7 and reflector 12 are then brought together. The rear side 10 of the substrate 7 may additionally be provided with a reflective layer (not shown). However, it is also already possible for the substrate 7 to be reflective due to reflection particles embedded in the PET material.

Fig. 3 shows the lighting device 2 in an oblique view, namely looking from that back space on it, in which the partial areas 7a are folded into it. The partial areas 7a are in each case folded out to a rear side 10 of the substrate; this back 10 faces the just mentioned rear space, in which the lighting device then emits the light.

4 illustrates how the light from the lighting device 2 according to the invention is illustrated by means of two schematic diagrams with obliquely employed partial areas due to multiple reflections per LED 8 already illuminated a comparatively large area of the lens 4. These areas, each illuminated over a large area, overlap, resulting in a comparatively good homogeneity of the illuminance on the entrance side.

For comparison, FIG. 4b shows a (not according to the invention) arrangement in which the LEDs 8 are arranged on a substrate without partial regions and illuminate the diffusing screen 4 directly. The main propagation direction 11 of the light emitted by one of the LEDs 8 is perpendicular to the entrance side 5 of the lens 4. The area of the lens 4 illuminated by each LED 8 is significantly smaller than in the case of FIG. 4a. Accordingly, in order to achieve the same illumination intensity distribution on the exit side 6 of the diffusing screen 4 as in FIG. 4 a, the diffusing screen 4 must be provided with greater scattering and / or a greater distance between the LEDs 8 and the diffusing screen. The latter is disadvantageous in terms of a compact design, the increased scattering deteriorates the efficiency.

Claims

Lighting device (2) for emitting light, with

a planar substrate (7),

a printed conductor structure (22) on the substrate (7), a plurality of LEDs (8) mounted on the substrate (7) and electrically conductively connected to the printed conductor structure (22),

wherein a plurality of subregions (7a) of the substrate (7) are partially separated from the remaining substrate (7b), each having a parting line (23) passing through the substrate (7) in the thickness direction but partially open in its longitudinal extension, that is, each still over one Bridge region (24) are connected to the remaining substrate (7b),

which parting lines (23) extend in each case to an edge of the substrate (7) spaced with respect to its surface directions completely within the substrate (7),

in which partial areas (7a) at least one of the LEDs (8) is mounted in each case and which partial areas (7a) are also folded out of the rest of the substrate (7b) around the bridge area (24) and are set obliquely therefrom.

Lighting device (2) according to claim 1, wherein the remaining substrate (7b) on the substrate (7) makes up an areal proportion of at least 30% and the remaining substrate (7b) is planar at least where the areas 7a) are arranged. Lighting device (2) according to claim 1 or 2, wherein the substrate (7) is made of a plastic material.

Lighting device (2) according to one of the preceding claims, comprising a support (12) on the substrate (7) which adjoins the substrate (7) with respect to the thickness direction, the support (12) having a higher bending stiffness than the substrate (7 ) Has .

A lighting device (2) according to any one of claims 1 to 3, comprising a planar reflector (12) on the substrate, which adjoins the substrate (7) with respect to the thickness direction, the reflector (12) being made of a material having a reflectance of at least 60% is taken.

Lighting device (2) according to claim 5 in conjunction with claim 4, in which the support (12) is at the same time the reflector (12).

Lighting device (2) according to one of claims 1 to 6, wherein the partial areas (7a) are folded out to a back (10) of the substrate (7), which rear side (10) of a front side (9) of the substrate (7), on the LEDs (8) are mounted, is opposite. Lighting device (2) according to Claim 7 in conjunction with Claim 5 or 6, in which the reflector (12) is arranged on the front side (9) of the substrate (7) and is interrupted (13) by the folded-out portions (7a). extends in the remaining substrate (7b) away, preferably without interruption.

Lighting device (2) according to one of claims 1 to 6, in which the subregions (7a) are folded out to a front side (9) of the substrate (7) on which front side (9) the LEDs (8) are mounted.

A lighting device (2) according to any one of the preceding claims, wherein the substrate (7) has a thickness of at least 150 ym and at most 500 ym and the wiring pattern (22) has a thickness of at least 20 ym and at most 100 ym.

Luminaire (1) with a lighting device (2) according to one of the preceding claims and a lens (4) which is relative to the

Lighting device (2) is arranged so that at least part of the of the

Lighting device (2) emitted light passes through the lens (4). Method for producing a

Lighting device (2) according to one of claims 1 to 10 or a lamp (1) according to claim 11, comprising the steps:

Providing the substrate (7);

Inserting the parting lines (23);

Folding out the subregions (7a) from the remaining substrate (7).

The method of claim 12, wherein the parting lines (23) with a mechanical

Cutting tool, in particular a punching tool, or be introduced by laser cutting. 14. The method according to claim 12 or 13, wherein the conductor track structure (22) upon folding out of the partial areas (7a) is locally plastically deformed.

15. The method according to any one of claims 12 to 14, wherein the LEDs (8) when folding out the

Subareas (7a) are already mounted on the substrate (7).

Method according to one of Claims 12 to 15 for producing a lighting device (2) according to one of Claims 4 to 6, optionally also in conjunction with one of Claims 7 to 10, in which the substrate (7) after folding out the partial regions (7a) on the support (12) and / or the reflector (12) is arranged.