DE102013214237A1 - Lighting unit with optoelectronic component - Google Patents

Abstract

The present invention relates to a lighting unit with a substrate body provided as a molded circuit carrier of a plastic material with an at least partially concave surface on which a plurality of optoelectronic components are arranged, wherein a part of the light emitted by a first of the plurality of components falls onto the surface of the substrate body and this partial shading of the light co-determines the spatial radiation characteristic of the lighting unit.

Description

Technical area

The present invention relates to a lighting unit with a substrate body and an optoelectronic component.

State of the art

Compared with conventional incandescent or even fluorescent lamps, currently developed optoelectronic light sources can be distinguished by improved energy efficiency. In the context of this disclosure, the terms "optoelectronic component" and "LED" refer to a radiation-emitting optoelectronic component made of a semiconducting material, for example an inorganic or even organic light-emitting diode.

The present invention is based on the technical problem of specifying a particularly advantageous lighting unit with optoelectronic component.

Presentation of the invention

According to the invention, this problem is solved by a lighting unit having a substrate body with an at least partially concave surface and having a plurality of optoelectronic components which are designed to emit light on a respective radiating surface during operation, a first component of the plurality of components on the surface of the substrate body arranged that a part of the light emitted at the emission surface of the first component light falls on the surface of the substrate body, and wherein the substrate body is provided as Urgeformter, in particular injection molded or extruded, circuit carrier made of a plastic material and by the partial shading of the light, the spatial radiation pattern the lighting unit co-determined.

The partial shading generally takes place for at least one "first component", which is also referred to by the concretizations of the dependent claims. Preferably, however, the corresponding relationships also apply to a "second component" and also to further components, namely, for example, in this order increasingly preferably at least 25%, 50%, 75% of the components or all components.

A substrate body provided for the lighting unit according to the invention fulfills various functions, which can increase the depth of integration and thus simplify overall construction and production. Thus, the substrate body initially serves as a carrier, which holds the components in a spatial arrangement to each other. Furthermore, a part of the light emitted at the emitting surface (s) of the component (s) strikes the surface of the substrate body, serves this purpose by this partial shading and, if appropriate, a reflection which is explained in more detail below, thus also the beam shaping. The substrate body itself is preferably not transmissive, in particular there is no diffuse transmission, although of course transmissive regions can be incorporated into the substrate body.

In this case, the substrate body is provided as urgeformter circuit substrate, so it also integrates a track function; For example, the components may be connected to one another via an integrated strip conductor structure and / or also to a driver and / or control electronics. By contrast, a printed circuit board known from the prior art for wiring a component, on the other hand, offers no freedom of design in three dimensions, and further components are necessary for light shaping.

The substrate body of the illumination unit according to the invention, on the other hand, is provided with an at least partially concave surface and partially shadows, depending on the viewing direction of the illumination unit, the emission surfaces of the component (s). In other words, the bundle of rays emitted by a single component, in many cases a Lambertian bundle of rays, is itself shaped by the substrate body carrying the components, and the substrate body "cuts" certain angles out of the bundle of rays by the shading. The shadowed (cut out) light can be absorbed and / or reflected by the substrate body.

An inventively provided substrate body thus advantageously combines a beam-forming function, ie optical properties, and serves as a structural element also the assembly of the components and optionally the heat dissipation of these, wherein the substrate body is ideally at the same time carrier of a conductor track structure, preferably an integrated conductor track structure, so the provides electrical contacting of the components.

The inventors have found that a possible disadvantage of a urgeformten substrate body made of a plastic material, such as a thermoplastic material, compared to, for example, a FR4 circuit board may optionally be in a poorer heat conduction and correspondingly poorer cooling. For the A lighting unit according to the invention therefore provides a plurality of components, so that the total power loss advantageously distributed to the substrate body, so at least not concentrated on a single point.

The lighting unit comprises at least two components, in this order increasingly preferably at least 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50 components.

Regardless of the number of components, the substrate body should preferably each have a certain minimum thickness in the respective areas below the components, for example of at least 2 mm, 4 mm, 6 mm, 8 mm or 10 mm; For example, possible upper limits may be 20 cm, 15 cm, 10 cm, and 5 cm, respectively. The "minimum thickness" is measured in the direction of the centroid beam of the respective component.

The term "component" or "LED" may mean both a self-contained and generally also an unhoused LED; In general, therefore, for example, an LED chip itself can be placed on the substrate body, such as a flip-chip. Preferably, however, already previously housed components are arranged on the substrate body, which thus each have their own housing (in a case can also be provided a plurality of LED chips); "Housing" means insofar a certain, not necessarily complete sheath with, for example, a potting material, usually together with one of the electrical and / or thermal contacting serving carrier plate.

An "original molded circuit carrier" may, for example, be an extruded part (extruded circuit carrier) and preferably an injection molded part (injection-molded circuit carrier). The "pre-formed" circuit carrier is a solid body made from a previously usually shapeless fabric.

The term "injection-molded circuit carrier" refers to a body that is released by a cavity, which was previously supplied with flowable material, at least within certain limits, which is at least partially hardened in the cavity. Preferably, it is supplied under elevated pressure, for example at least 100 bar, 500 bar, or 1000 bar; Possible upper limits may be around 3000 bar, 2500 bar or 2250 bar. The hardening can be carried out, for example, at a hardening temperature which is different from the feed temperature, for example at lower temperatures in the case of a thermoplastic material and at higher temperatures in the case of a thermosetting material.

Polypropylene (for example PA6, PA66, PA10, PA11, PA12), in particular high-temperature-resistant polyamide such as PPA or PA46, polyester (for example PBT, PET, PBT / PET, PCT , ABS, ABS / PC), polyphenylene sulfide, LCP and / or PEEK.

The surface of the urgeformten substrate body is in any case "partially concave", d. H. a plane including the radiating surface of the (first) device intersects the surface; This preferably applies to all components of the plurality. In general, of course, the radiating surfaces need not be flat and, to that extent, this refers to a planarly approximated radiating surface.

As far as in the context of this disclosure reference is made to the propagation of radiation or light, this of course does not mean that a corresponding spread must occur to fulfill the object; the lighting unit should be designed for a corresponding spread. The terms "radiation" and "light" are used interchangeably in the context of the disclosure, and may generally also include ultraviolet or infrared electromagnetic radiation, and preferably refer to the visible region of the spectrum.

Preferred embodiments can be found in the dependent claims and further in the description. The presentation does not distinguish in detail below between the different categories of entitlements; In any case, the disclosure is implicitly to be read with regard to a lighting unit, a corresponding lamp and respective manufacturing, operating or use aspects.

In a preferred embodiment, the first of the components and the substrate body are provided in such a way that at least the light propagating within a contiguous first shading angle range of 20 ° falls on the substrate body in a sectional plane containing the centroid beam of the first component. The vertex of the shading angle lies at the intersection between the center of gravity and the radiating surface.

The shading angle range may be increasingly preferably at least 30 °, 40 °, 50 °, 60 °, 70 °, 80 ° and 85 ° in this order. The "centroid ray" results as a centroid ray of the power weighted rays the beam emitted from the corresponding device; For example, in the case of a rectangular, Lambertsch emitting radiating surface, it lies in the center of the surface perpendicular to the radiating surface.

In a preferred embodiment, the shading angle range is maximally tilted with respect to the center of gravity beam - the shading angle range is an area "filled with light", ie the beam emitted by the component should be shaded starting from the edge (maximum tilt angle). In other words, therefore, starting with shadows that are maximally tilted with respect to the centroid ray. Depending on the extent of the shading angle range, this can then extend to the center of gravity beam or even beyond.

All this is preferably true not only for the first component, but also for a second component and particularly preferably further components, for example at least 2, 5, 8 or 10 components.

In a preferred embodiment, a second device of the plurality of devices is disposed in the region of the surface on which a portion of the light emitted by the first device falls directly (without prior reflection). This is particularly preferably in pairs for at least 25%, 50%, 75% of the components or all components. In general, however, the surface in addition to the concave shape could of course also be formed locally convex, so could just shadow, for example, a local elevation between two components this relative to each other.

In a preferred embodiment, an area of the surface, in which components are arranged, viewed in a sectional plane containing the total center of gravity beam of the illumination unit has a shape corresponding at least in sections to a conic section; the "center of gravity beam" is formed as the mean value of the total, weighted by the power unit emitted by the illumination unit and corresponds approximately in the case of a radiation characteristic with rotational symmetry of the axis of rotation.

Thus, the concave surface (seen in said section plane) has sections of a "shape corresponding to a conic section", so it can describe a part of an ellipse or a circle or even a hyperbola or parabola; "Section wise" may mean, viewed from a focal point of the conical shape, a shape extending over an angular range of at least 45 °, 90 ° or 135 °.

In a preferred embodiment (which may be particularly preferably combined with a conical shape), the surface is cup-shaped, for example U-shaped or V-shaped, in a sectional plane that includes the entire center of gravity beam, and a preferably peripheral edge of this cup shape jumps over a region of the surface. on which the components are arranged, back inwards. In other words, a surface portion of the substrate body defines a cavity (the cup shape) and partially conceals it by a collar (the recessed edge).

The "surface area" can be defined, for example, by an envelope tangent to the outer components of the arrangement or even extend as far as a region in which the curvature direction of the substrate body surface changes, for example in a sectional plane containing the entire centroid beam, and this therefore becomes convex ,

This embodiment with "collar" is of particular interest in the case of components which emit light of different color, because a light mixture can take place in the cavity and the recessed edge region at the same time conceals the direct view of at least some of the components. The recessed edge region is in some respects an "undercut", which can be realized in a particularly advantageous manner with an injection-molded or extruded circuit carrier provided according to the invention.

In a preferred embodiment, the substrate body is integrally formed, ie as a monolithic component without material boundary. Of course, this only applies to the substrate body itself providing the at least partially concave surface, a conductor track structure provided on the surface thereof being made of a metallic material.

In addition to the conductor track structure serving for electrical contacting of the components, it is generally also possible to apply structured coatings for directional and / or diffuse reflection or absorption in order to locally influence the optical properties of the substrate. Preferably, however, only the conductor track structure serving for electrical contacting is provided on the surface, and optical and / or thermal properties are set by particles embedded in the substrate body.

The "one-piece" embodiment therefore does not exclude particles randomly distributed therein that are embedded in the substrate body. An embedded in the substrate body additive can even (even independently one-piece) may be preferred, for example, to impart diffuse and / or directionally reflective or specifically absorbing properties to the surface; For this purpose, a color pigment is particularly preferably embedded in the substrate body, for example titanium dioxide particles.

In general, the provision of a diffusely reflecting surface (at least one surface area) may be preferred, which in general may also mean directional diffuse reflection and particularly preferably relates to uniformly diffuse reflection, for example by coating and / or roughening the surface. The reflectivity in the visible region of the spectrum can be, for example, in this order increasingly preferably at least 30%, 40%, 50%, 60%, 70%, 80% and 90%, particularly preferably based on a uniform diffuse reflection.

A directionally reflecting surface area may also be preferred, wherein, for example, a reflectivity of at least 90%, 95% or 98% may be preferred.

In any case, since the absorption is reduced, the efficiency of the lighting unit can be increased. Since the preferred reflection is diffuse, the light beams are therefore not reflected as in a geometric image, but with a certain random distribution in terms of directions, advantageously a detail making reflective mirroring of the components can be avoided and give the impression of a more uniform illumination.

Incidentally, an additive may additionally or independently also fulfill a different function, that is, for example, (also) an additive for increasing the thermal conductivity of the substrate body may be provided, for example particles of an electrically non-conductive ceramic. For example, particles comprising BN, AlN, Al ₂ O ₃ and / or SiC, or particles consisting solely thereof, may be embedded in the substrate body. Despite the components provided in a plurality and the power dissipated correspondingly at least slightly distributed over the substrate body, the thermal conductivity of the substrate body is increased compared to that of the base material and can, for example, in this order increasingly preferably at least 2 W / (mK), 4 W / (mK) , 6 W / (mK), 8 W / (mK) and 10 W / (mK) respectively. Advantageously, then, for example, can be dispensed with a separate heat sink, which can simplify design and manufacture.

Furthermore, it is also possible to provide an additive for increasing the strength of the substrate body (in addition to increasing the reflectivity and / or conductivity or else independently of this), which may increase the freedom of shaping, in particular minimum thicknesses. Thus, for example, fibers may be embedded in the substrate body, for example glass fibers and / or a mineral filler.

An optical element can also be integrated or integrated into the substrate body, that is to say in particular an optically transmitting element, such as a prism or grid. In general, a recess in the substrate body is conceivable, so that a part of the light can pass from a surface area provided with components to an opposite surface area.

In general, a symmetrically constructed substrate body may be preferred, for example a rotationally symmetrical substrate body. The substrate body can also be translationally symmetrical, that is to say resulting from displacement, preferably linear displacement, of a section, in particular in the case of an extruded circuit carrier.

A lighting unit is preferred in which a printed conductor structure for wiring the components is provided exclusively on the surface. In this case, through contacts or the like passing through the substrate body are dispensed with, that is to say onto the substrate body from a conductor track pieces penetrating through to the opposite surface, which in turn can simplify the production. Particularly preferably, the conductor track structure is provided exclusively on the "inner" surface region which also carries the components, and the opposite, "outer" surface region of the substrate body is free of the conductor track structure.

In principle, an ("inner") surface area carrying the components is preferably rather flat and not strip-shaped, ie the smallest and the largest extent of this surface area have, for example, a ratio of at least 1/5, more preferably at least 1/4, 1/3, 1 / 2 or 3/4; most preferably, the surface area is approximately square. Reference is made to the above definition of "surface area".

In a preferred embodiment, an outer surface area, which is opposite to the inner surface carrying the components surface area, provided as the outer surface of a lamp body. The lighting unit according to the invention must then be covered in a lamp not back with a housing element of the lamp, but is free in this respect.

In other words, not only the surface of the lighting unit emitting the light emitted from the components, but also an opposite outer surface contributes to the aesthetic impression that the lighting unit / light has on an observer. The invention also explicitly relates to such a luminaire and a corresponding use of a lighting unit.

In general, and independently of the specific embodiment just mentioned, the invention is also directed to a luminaire with a lighting unit described in the context of this disclosure. In general, "luminaire" may mean, for example, the device which connects via the mains to a power outlet or a clamping / screwing / soldering contact, in which case one or more lighting unit (s) can be seated, ie held.

The conductor track structure can in principle be applied, for example, in the context of a multicomponent injection molding, with the substrate body being injection-molded as one component and, for example, a metallizable plastic as another component, which is subsequently galvanically coated, for example. In an injection molding tool and a carrier with the conductor track structure can be inserted and back-injected. Furthermore, the conductor track structure can also be embossed, for example, in a hot embossing process onto the previously injection-molded substrate body, for example starting from a metal foil which is also punched in the embossing press.

It is also possible to apply the printed conductor structure by laser direct structuring, wherein a laser beam "writes" the printed conductor structure on the surface of the (injection-molded or extruded) substrate body, thereby exposing embedded microorganisms in the substrate body for subsequent metallization. On the other hand, the conductor track structure can also be applied with methods known from semiconductor manufacturing, ie by appropriate masking, wherein in exposed areas of a large-area applied (paint) mask, for example, the wiring structure can grow or a previously deposited metal layer (under the (paint) mask) are removed can, for example, by etching.

In a preferred embodiment, the light incident on the substrate body by the first of the components generates an irradiation intensity distribution with a maximum and a part of the light re-emitted in the region of this maximum falls on a region of the substrate body which is not directly from the first component is illuminated. The maximum of the irradiance distribution is effectively a virtual light source; the light emitted by this (re) light (like the light directly emitted by the components) can again be formed by the substrate body.

Particularly preferably, in a sectional plane containing the centroid beam of this virtual light source, a tangent to the substrate body emanating from the virtual light source may also approximately limit the radiation beam emitted by the illumination unit as a whole to the outside; that is, this outer area of the radiation beam is "supplied" by the virtual light source. Since the irradiance distribution has a certain course, the beam is then usually not "sharp" cut off and limited to the outside, but the intensity seen from the maximum, for example, over an angular range of at least 5 ° or 10 ° and at most 30 ° or Decrease 20 °.

For example, a "maximum of irradiance distribution" may be an increased power in a "maximum surface area" that may, for example, have a diameter of less than 40 mm, 30 mm, 20 mm, or 10 mm (the term "diameter" is not necessarily so to imply a circular geometry, but in general to read the mean of the smallest and largest extent); the average irradiance entering the maximum surface area may be greater than that in a surrounding area of about three, five or seven times the diameter, for example at least two, three, four or five times larger.

Particularly preferably, the virtual light source also has a shading angle range, and it should be expressly disclosed for this also the preferred angles and arrangements given above for the first shading angle range.

A preferred embodiment relates to a set of at least two lighting units. These at least two lighting units differ in the arrangement of the respective plurality of components, but are characterized by identical substrate body; The arrangement of the components differs in such a way that the two lighting units have a different emission characteristics.

The radiation characteristic of the components of the sentence can be "different" insofar as considered in the same sectional plane polar diagrams (with, for example, the maximum power normalized performance) to at least 10%, 20%, 30%, 40% and 50% are not congruent related to the larger area inclusive polar diagram. With only one type of substrate body and accordingly only one injection molding tool or only one die in the case of extrusion, it is possible to realize different illumination units, which can increase the modularity and reduce manufacturing costs.

The invention also relates to a method for operating the illumination unit, wherein (at least) the first component emits light of different intensity in (at least) a first and a second operating state, that is, for example, in its order more preferably in its intensity by at least 20%, 30%, 40% and 45% differing light, respectively. The lighting unit has, due to a different shading, in the first and the second operating state, a different emission characteristics, and it is referred to the definition of "different" in the preceding paragraph.

Preferably, the total center of gravity beam in the second operating state is tilted by at least 10 °, in this order increasingly preferably at least 20 °, 30 °, 40 °, 50 °, 60 °, 70 °, with respect to the first operating state. This should also be disclosed for the above described set of at least two lighting units, so that their respective total centroid beams should preferably be tilted accordingly.

The invention also relates to the use of a lighting unit or a luminaire with such a lighting unit for general lighting, in particular for lighting with a stationary lamp, preferably for illuminating a building, such as its immediate environment or preferably its interior, in particular for illuminating a work surface, such as a desk. Particularly preferably, a suitably used lighting unit can be operated in a manner described in the preceding paragraphs.

Brief description of the drawings

In the following, the invention will be explained in more detail with reference to exemplary embodiments, wherein the individual features may also be essential to the invention in another combination and should be disclosed in this form.

In detail shows:

1 a first illustration of a lighting unit in an oblique view;

2 a sectional view of the embodiment according to 1 ;

3 the intensity distribution of the lighting unit according to the 1 and 2 in a polar diagram;

4 a virtual light source on the surface of the substrate body of the lighting unit according to the 1 to 3 namely, a maximum of the irradiance distribution;

5 a lighting unit according to the invention in an oblique view;

6 the lighting unit according to 5 in a sectional view;

the 7a , b, c intensity distributions of the lighting unit according to the 5 and 6 in different operating states;

the 8a , b, c a further illumination unit according to the invention in an oblique view, a side view and a bottom view;

9 the intensity distribution of a lighting unit according to the 8a , b, c in a polar diagram;

the 10a , b, c, the intensity of the red, green and blue light upon exiting the lighting unit according to the 8a , b, c.

Preferred embodiment of the invention

1 shows in this respect no complete lighting unit according to the invention 1 , as on the substrate body 2 for clarity, only one component 3 , So only one of the actually provided in plurality LEDs is shown. The conductor track structure used for contacting the LED is likewise not shown, but lies together with the LED (s) on the same surface area of the substrate body 2 , ie the "inner" surface area on which 1 the view falls. The opposite "outer", in 1 invisible surface area represents an outer surface of a lighting unit according to the invention 1 carrying light.

2 shows the lighting unit according to 1 in a sectional view, wherein the sectional plane in a total center of gravity beam 21 the lighting unit 1 containing level lies. The overall center of gravity beam 21 arises as a result of the basis of 3 explained in more detail radiation, so by the LED 3 with the center of gravity beam 21 emitted light and its partial shading by or reflection on the substrate body 2 certainly. (In an actual lighting unit 1 affect one Plurality of LEDs 3 with respective center of gravity beam 22 the overall center of gravity beam 21 .)

The LED 3 and the substrate body 2 are in this case arranged to each other such that the center of gravity beam 22 tangential to the substrate body 2 lies. Accordingly, half of the LED drops 3 Lambertsch emitted light on the substrate body 2 and is diffusely reflected by it, specifically by embedded therein titanium dioxide particles.

3 shows the resulting in the far field intensity distribution this (exemplary) with only one LED 3 powered lighting unit 1 , in a polar diagram with intensity normalized to the maximum intensity. For orientation and comparison with 2 are a first straight line 25 and a second straight line 26 drawn in, which essentially limit the beam.

In the angular range between about 55 ° and 65 ° there is an intensity decreasing towards 65 °, although that of the LED 3 directly emitted light at 65 ° has its maximum intensity, cf. the center of gravity beam 22 in 2 , The reason for this is that the distribution at the maximum is not simply cut off by the substrate, but light diffusely reflects and accordingly the intensity is amplified at angles <60 °. The substrate body 2 serves the beam shaping, so determines the emission with.

The second straight line 26 is not at an angle to that of the in 2 left leg of the substrate body 2 corresponds (this would be at about -25 °), but a bit far "flatter", namely at -40 °. Thus, due to the reflection on the substrate body, an angular range is illuminated, in the case of viewing the LED 3 alone or in the case of a perfectly absorbent substrate body 2 no light would fall.

4 illustrates the formation of the flatter second straight line 26 , The figure shows the lighting unit 1 in a supervision, namely (based on the orientation according to 2 ) from below onto the surface of the substrate body 2 looking back.

That from the LED 3 on the substrate body 2 falling light generates on this an irradiance distribution, which in 4 represented by contour lines. It can be seen that the irradiance distribution near the apex of the substrate body 2 , at the upper end of the right long thigh a maximum 41 Has. Its location is also in the sectional view according to 2 indicated by a corresponding circle. Because in this surface area so much light from the LED 3 is incident, also correspondingly much light is re-emitted; the range of the maximum 41 represents in this respect a virtual light source. The light that is re-emitted by it becomes (like that directly from the LED 3 emitted light) partially from the substrate body 2 shaded; from a corresponding tangent results in the beam approximately limiting second straight line 26 ,

5 shows a lighting unit according to the invention 1 with a substrate body 2 on which a first LED 3a and a second LED 3b are arranged. Also conceivable is a lighting unit 1 formed as an elongated body and, for example, in total 50 LEDs 3 is provided, wherein 5 then one of 25 juxtaposed sections show that the lighting unit could thus be constructed by linear displacement of the section.

6 shows the lighting unit 1 according to 5 looking at it in a side view, it is again the first one 3a and second LED 3b on the substrate body 2 arranged to recognize. The first left leg in the figure of the substrate body 2 on which the first LED 3a is arranged, and the second, in the figure right leg of the substrate body 2 on which the second LED 3b is arranged perpendicular to each other. Accordingly, also the first 22a and the second centroid ray 22b perpendicular to each other.

The 7a , b, c show the intensity distribution of the illumination unit 1 according to the 5 and 6 in polar diagrams, for three different operating states.

In the first, in 7a shown operating state is alone the first LED 3a operated, so determined by this directly emitted light and that of the substrate body 2 Re-emitted light (the original also from the first LED 3a originates) the emission characteristic. For orientation and comparison with 6 is the first straight line 25a which delimits the beam "to the right". The first straight 25a results in 6 as the base of the centroid ray 22a outgoing tangent to the substrate body 2 , The substrate body 2 shaded in the first operating state so a range with angles> 65 °, and there is a total center of gravity beam 21a which is at an angle of about 25 °.

The lighting situation according to 7c in which only the second LED 3b is operated in mirror symmetry (with respect to the 0 ° axis). The overall center of gravity beam 21b is about -25 °, and the first straight line 25b limits the beam to the left. By switching between the two operating states ( 7a and 7c ) can be the orientation of the center of gravity beam 21 So be changed by about 50 °, which may be about in the selective illumination of a work surface of interest.

7b shows a third operating state, in which the first 2a and the second LED 2 B (which are identical in construction) are operated with the same power, ie emit light of the same intensity and distribution. The power of each LED 3a , b is chosen so that for the three operating states ( 7a , b, c) gives the same overall performance; in the 7b illustrated operating state, the LEDs 3a , ie operated at half power.

The overall center of gravity beam 21 located in 7b at 0 °, and the beam is transmitted through on both sides by the first two straight lines 25a , b limited. Of course, the two LEDs could 25a , b also be operated at full power, and thus could reinforce the illumination in the 0 ° range. In the case of the above-mentioned illumination of a work surface, such an operating state could thus be selected in the case of a particularly detailed work, whereas the operating states according to FIGS 7a and 7c For example, it may help to reduce glare.

The 8a , b, c show a further lighting unit according to the invention 1 , in an oblique view from below ( 8a ), in a side view ( 8b ) and in a top view ( 8c ). The substrate body 2 is hollow spherical in this case, thus corresponds to a hollow spherical shape cut below its midpoint.

The substrate body 2 thus forms a partially open hollow sphere whose inner surface on which the LEDs 3 are arranged, limited to a cavity. The opposite outer surface 81 represents a visible outer surface of the luminaire.

On the inner surface are the LEDs 3 statistically distributed, with LEDs 3 three different colors (red, green, blue) are provided; Mixing the red, green and blue light produces white light.

9 shows for the lighting unit 1 according to 8th an intensity distribution in a polar diagram. The light enters the light exit surface 82 , ie the opening of the hollow spherical shape, and has approximately a Lambertian characteristic ( 9 ).

The exit surface 82 is tapered with respect to the inner diameter of the hollow sphere, in the plan view from below according to 8c is an inside (based on the distance to the total center of gravity beam 21 ) recessed collar 83 to recognize, that is the light exit surface 82 rejuvenated.

The 10a , b, c show the intensity distribution of the red ( 10a ), green ( 10b ) and blue ( 10c ) at the exit surface 82 leaking light, each normalized to the maximum intensity. For each color, the intensity curve is for two in the exit surface 21 lying straight lines 101 . 102 represented, respectively, by the center of the exit surface 82 run and are perpendicular to each other.

From the 10a , b, c it can be seen that, for each of the three colors, the course of the relative intensity over the exit surface 82 apart from smaller fluctuations, it is comparatively uniform. Accordingly, the red, green and blue light in the cavity is well mixed, so the white light emitted shows only a small fluctuation in the color locus depending on the spatial coordinates.

Claims (15)

Lighting unit ( 1 ) with a substrate body ( 2 ) with an at least partially concave surface and with a plurality of optoelectronic components ( 3 ) configured to emit light in operation at a respective radiating surface, wherein a first component ( 3 ) of the plurality of components ( 3 ) on the surface of the substrate body ( 2 ) is arranged such that a part of the at the radiating surface of the first component ( 3 ) emitted light on the surface of the substrate body ( 2 ), and wherein the substrate body ( 2 ) is provided as urgeformter circuit substrate made of a plastic material and by the partial shading of the light, the spatial radiation characteristics of the lighting unit ( 1 ). Lighting unit ( 1 ) according to claim 1, wherein a first component ( 3 ) of the plurality of components ( 3 ) and the substrate body ( 2 ) are provided in such a way that in one the center of gravity beam ( 22 ) of the first component ( 3 ) considers the light propagating within a contiguous first shading angle range of at least 20 ° onto the substrate body ( 2 ) falls. Lighting unit ( 1 ) according to claim 2, wherein the first shading angle range relative to the center of gravity beam ( 22 ) is maximum tilted. Lighting unit ( 1 ) according to any one of the preceding claims, wherein a second Component ( 3 ) of the plurality of components ( 3 ) is arranged in the region of the surface on which a part of the at the radiating surface of the first component ( 3 ) emitted light falls directly. Lighting unit ( 1 ) according to one of the preceding claims, in which the surface on which the components ( 3 ) are arranged in one the total center of gravity beam ( 21 ) of the lighting unit ( 1 considered sectional plane considered an at least partially has a conic corresponding shape. Lighting unit ( 1 ) according to any one of the preceding claims, wherein a portion of the surface in one of the centers of gravity ( 21 ) considered cutting plane is pot-shaped and an edge of this pot shape springs back inside. Lighting unit ( 1 ) according to one of the preceding claims, in which the substrate body ( 2 ) is integrally formed. Lighting unit ( 1 ) according to one of the preceding claims, in which the substrate body ( 2 ) at least partially has a diffuse-reflecting surface, preferably due to a in the substrate body ( 2 ) embedded additive. Lighting unit ( 1 ) according to one of the preceding claims, preferably in conjunction with claim 8, in which that of the first component ( 3 ) of the plurality of components on a reflective region of the substrate body ( 2 ) falling light on this one irradiance distribution with a maximum ( 41 ), wherein a part of the region of the maximum ( 41 ) re-emitted light onto a region of the substrate body ( 2 ), which is not directly illuminated by the first component. Lighting unit ( 1 ) according to one of the preceding claims, in which exclusively on the surface, a conductor track structure for contacting the plurality of components ( 3 ) is provided. Lighting unit ( 1 ) according to one of the preceding claims, in which at least one surface region of the substrate body ( 2 ), one of the components ( 3 ) supporting surface area is arranged opposite, is provided as the outer surface of a lamp. Set of at least two lighting units ( 1 ) according to one of the preceding claims, wherein the substrate body ( 2 ) of the at least two lighting units of the set are identical to one another, the at least two lighting units ( 1 ) but in the arrangement of the respective plurality of components ( 3 ) on the respective surface in such a way that the at least two lighting units ( 1 ) differ in terms of their spatial radiation characteristics. Method for operating a lighting unit ( 1 ) according to one of claims 1 to 11, in which the first of the plurality of components ( 3 ) emits light of different intensity in a first and a second operating state, so that the illumination unit ( 1 ), due to a different shading, in the first and the second operating state has a different spatial radiation characteristics. The method of claim 13, wherein the overall centroid beam ( 21 ) is tilted in the second operating state by at least 10 ° relative to the first operating state. Use of a lighting unit ( 1 ) according to one of claims 1 to 11 for general lighting, in particular for illumination with a stationary lamp, in particular for illuminating a building, in particular for the interior lighting of a building.

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