DE102012218059A1 - LED lamp for generating predeterminable distribution of luminous intensity in photometric far-field, has reflector arranged opposite to carrier element, where upper surface of carrier element comprises three-dimensional structure - Google Patents

Abstract

The lamp (20) has a set of LEDs (14) arranged in a region of a carrier element (22). The region of the carrier element is designed as an upper surface (24) of the carrier element. A planar or three-dimensional formed reflector (26) is arranged opposite to the carrier element such that a light of the LED is partially reflected at the reflector. The upper surface of the carrier element comprises a three-dimensional structure, and the reflector comprises a reflective silver layer. The upper surface of the carrier element comprises two regions, which are approximated by a plane. An independent claim is also included for a method for manufacturing an LED lamp for generating a predeterminable distribution of luminous intensity.

Description

Technical area

The invention relates to an LED lamp according to the preamble of patent claim 1 and a method for producing an LED lamp according to the preamble of patent claim 7.

State of the art

Luminaires are known from the prior art which, in order to produce a specific emission characteristic, such as a Batwing luminous intensity distribution, have very complex optics, such as e.g. Batwing lenses or elaborately shaped reflectors having. For example, relatively complex and thus expensive 2D and 3D optics or reflectors are required for lights and car headlights, which show a special radiation in the photometric far field such as Batwing, Spot, Wallwasher or asymmetry. Injection molded parts are formed and chrome plated for complex reflectors, whose reflectance is relatively low (about 83%).

In 1a is an example of a street lamp 10 represented according to the prior art. This comprises an LED module arrangement 12 , in the 1b is shown enlarged again. The LED module arrangement 12 has a plurality of LED modules 13 on. Such a LED module 13 is in 1c shown. This includes a plurality of LEDs 14 and a complex shaped, in particular faceted reflector 16 to produce a desired illumination distribution on the road. The structural design of this LED module 13 comprising a circuit board 18 or a circuit board having a plurality of LEDs disposed thereon 14 and a faceted reflector 16 , is in 1d again shown schematically.

The disadvantage here is that the reflectors to produce a desired light distribution in the photometric far field must be very complex and thus are very expensive and expensive to produce. In addition, the complex production of the reflectors, which must be deformed, rolled or pressed, that such complex reflectors can be implemented with only relatively low reflectivities.

Presentation of the invention

The object of the present invention is to provide an LED luminaire and a method for producing an LED luminaire, by means of which a specifiable luminous intensity distribution can be generated with less effort.

This object is achieved by an LED lamp having the features of patent claim 1 and a method having the features of patent claim 7.

Particularly advantageous embodiments can be found in the dependent claims.

The LED luminaire according to the invention for generating a predefinable light intensity distribution in the photometric far field comprises a carrier element and a plurality of LEDs arranged on the carrier element, wherein the region of the carrier element in which the LEDs are arranged is defined as a surface of the carrier element. Furthermore, the LED lamp comprises a reflector, which is arranged in such a way with respect to the carrier element, that light of the LEDs is at least partially reflectable on the reflector. In this case, the surface of the carrier element has a three-dimensional structure.

The three-dimensional structure of the surface is understood to mean that the surface, ie the region of the carrier element in which the LEDs are arranged, is at least not completely in one plane, in contrast to the planar circuit boards commonly used in the prior art where the LEDs are arranged.

The three-dimensional structure of the surface can be designed such that the spatial arrangement and emission direction can be predetermined by the geometry of the three-dimensional structure due to the geometry of the surface and the LEDs arranged thereon. This makes it possible to produce a predefinable light intensity distribution in combination with a very simply designed reflector. In particular, the design of the surface of the carrier element with a three-dimensional structure makes it possible to design the reflector with a very simple geometry. Thus, by means of this simple and particularly advantageous arrangement in the far-field photometric field, a light intensity distribution such as, for example, a Batwing light intensity distribution or a spot can be produced without requiring expensive and complex-shaped optics or reflectors.

In an advantageous embodiment of the invention, the reflector may be configured flat or three-dimensional.

Three-dimensional means in this context not that the reflector has a volume or a thickness not equal to 0, but is based on the surface geometry of the reflector. That that a surface of the reflector in a three-dimensional design of the reflector, at least not completely in a plane.

In a three-dimensional refinement of the reflector, in combination with the three-dimensional surface structure of the carrier element of the LED luminaire, a multiplicity of desired, specifiable luminous intensity distributions can be realized in a very simple manner. For the generation of a desired light intensity distribution, it is thus possible to use reflectors which are much less elaborately designed with respect to the complexity of their geometry, which are therefore also less expensive and less expensive to produce. Of course, even more complex shaped three-dimensional reflectors can be used. Especially in combination with the three-dimensional surface structure of the support element can thus be implemented in a particularly advantageous manner and extremely complex emission characteristics of the LED lamp, as they were previously not possible in the art with planar support elements.

Particularly advantageous is the formation of the reflector as a planar reflector. The flat reflector does not need to be deformed, rolled or pressed, and its surface remains uninjured. Thus, the reflector can be made much cheaper and at the same time, the reflectance of the reflector can be increased.

In the design of the reflector, both a three-dimensional and a flat, a variety of options are available. The reflector may be metallic or non-metallic, e.g. made of porcelain, plastic, shiny materials, etc. In addition, the surface of the reflector may also be coated or have a surface of glass, porcelain, glossy materials with Fresnel reflection and / or high reflection in incident light. The reflector may also be of mixed materials and have combinations of non-metallic materials with metals, as well as combinations of diffused and directionally reflective surfaces.

In an advantageous embodiment of the invention, the reflector may have a reflective silver layer, in particular, the reflector may be made of aluminum and have a highly reflective silver layer. Optionally, the reflector may also have a diffusely reflecting, white plastic film with a porous structure. Due to the porous structure of the film, on the one hand, the diffuse scattering of the light is due, on the other hand, this also allows enormously high reflectance. The simple geometry of the reflector provided by the invention, in particular with a planar design of the reflector, allows the use of such highly reflective layers and films. Such layers and films can not be used in complex designed reflectors, since in the formation of these reflectors tear these layers and would be damaged. By a flat reflector, it is thus possible to increase the reflectance of the reflector considerably. In particular, it is thus possible to achieve reflectivities which are more than 95%, in particular even more than 98%.

In an advantageous embodiment of the invention, the surface of the support element on at least two areas, which are each approximable by a plane, wherein the planes form an angle with each other, which is different from 180 °. Preferably, the surface of the carrier element may also be in the form of two intersecting planes. The angle of intersection or the angle that the planes enclose with one another can be dimensioned such that a desired emission characteristic can be achieved by the LEDs arranged on the surface in accordance with a predetermined light intensity distribution. In addition, the inclination of the reflector, in particular a planar reflector, with respect to the carrier element is variable. This inclination angle, in particular the angle of inclination of the planes which approximate the surface of the carrier element, can also be adjusted or dimensioned such that a predefinable light intensity distribution, such as batwing or spot, can be generated in the far field. It is particularly advantageous in this embodiment that a plurality of predefinable light intensity distributions in the far field can be generated by very simple geometries, both those of the reflector and those of the carrier element.

In addition, a variety of ways are available to design the support element.

In an advantageous embodiment of the invention, the carrier element may comprise a base body on which at least one printed circuit board is arranged with a plurality of conductor tracks. This is particularly advantageous in a design of the surface of the carrier element as flat surfaces. On the body, which is preferably made of a metal, for example, a flexible circuit board can be glued. This embodiment is particularly simple and inexpensive and is particularly suitable for simpler geometries of the support element.

In a further advantageous embodiment of the invention, the carrier element may be formed as a base body with a plurality of conductor tracks. In this case, the conductor tracks or else metal pads and plated-through holes can be produced by direct laser structuring or by embossing a structured metal foil on the base body. The main body can be formed from a plastic, preferably from a thermoplastic, partially metallized plastic, which is particularly well suited for the production of printed conductors by laser direct structuring. By extrusion or injection molding, any geometry of the base body and in particular its surface can be realized, wherein the geometry of the base body can be advantageously adapted to the desired emission characteristic of the LED light to be generated. Thus can be implemented by the large number of possible training variants of the main body of the LED light a variety of luminous intensity distributions, without the need for complex, expensive and complex optics or reflectors.

• – Herstellen eines Grundkörpers mit einer dreidimensionalen Oberflächenstruktur;
• – Erzeugen von Leiterbahnen mit einer dreidimensionalen Leiterbahnstruktur auf dem Grundkörper;
• – Anordnen von LEDs auf den Leiterbahnen; und
• – Anordnen eines Reflektors gegenüber dem Grundkörper in einem vorgebbaren Winkel, so dass Licht der LEDs zumindest zum Teil vom Reflektor reflektiert wird.

The method according to the invention for producing an LED lamp for generating a predefinable light intensity distribution comprises the steps:

• - Producing a base body with a three-dimensional surface structure;
• - generating conductor tracks with a three-dimensional conductor track structure on the base body;
• - Arranging LEDs on the tracks; and
• - Arranging a reflector relative to the base body in a predetermined angle, so that light from the LEDs is at least partially reflected by the reflector.

Producing a basic body with a three-dimensionally structured surface and arranging the basic body with the LEDs in relation to a flat reflector can be used to generate predefinable light intensity distributions, such as batwing, spotlights, wallwashers or with an asymmetry, without elaborately designing complex, expensive reflectors have to. These light intensity distributions can be implemented with a three-dimensionally formed reflector, but advantageously these light intensity distributions can also be realized with a flat reflector. By this method, thus, an LED lamp for generating a predetermined luminous intensity distribution in the far photometric field can be produced with significantly reduced effort.

In particular, the method is suitable for producing an LED lamp according to the invention or one of its design variants. All mentioned in connection with the LED lamp according to the invention advantages, features and design variants apply, as applicable, also for the inventive method.

Favor is while the main body is made by injection molding, which has the advantage that the base body can be arbitrarily shaped in its geometric configuration, depending on the desired radiation characteristics.

Furthermore, it is preferable to produce the printed conductors by means of laser direct structuring. In this way it is possible to very easily produce conductor tracks even on complex three-dimensional surface structures of the base body, without having to restrict oneself to the geometric configuration of the basic body.

Further advantages, features and details of the invention will become apparent from the claims, the following description of preferred embodiments and from the drawing.

Brief description of the drawings

In the following, the invention will be explained in more detail with reference to exemplary embodiments. The figures show:

1a a schematic representation of a street lamp with a LED module assembly according to the prior art;

1b a schematic representation of the LED module assembly 1a with a plurality of LED modules according to the prior art;

1c a schematic representation of an LED module of the arrangement 1b with a plurality of LEDs and a faceted reflector according to the prior art;

1d a schematic diagram of an LED module with a board on which LEDs are arranged, and a faceted reflector according to the prior art;

2 a schematic representation of an LED lamp with a reflector and an LED array on two areas of the surface of a support member, which are inclined at different angles to the reflector, according to an embodiment of the invention;

3 a schematic representation of a batwing light intensity distribution in the photometric far field of an LED lamp according to an embodiment of the invention;

4 a schematic representation of a light intensity distribution in the photometric far field of a fluorescent lamp with a complex reflector according to the prior art;

5 a schematic representation of an LED light, which is designed according to an embodiment of the invention as a spot or spotlights;

6 a schematic representation of a light intensity distribution in the far field of in 5 LED lamp shown as an embodiment of the invention;

7 a schematic representation of a support member of an LED lamp according to an embodiment of the invention, with two angled portions of a surface of the support element, in each of which a plurality of interconnects are arranged, and one on the interconnects statistically distributed LED array;

8th a schematic representation of a support member having two angled portions, each having a plurality of conductor tracks with contact elements, on which LEDs can be arranged, according to embodiment of the invention;

9a a schematic representation of a three-dimensionally structured main body of an LED lamp according to an embodiment of the invention;

9b a schematic representation of a three-dimensionally structured base body arranged thereon conductor tracks with contact elements, to which LEDs can be arranged, according to an embodiment of the invention;

9c a schematic representation of the on the base body 9b arranged conductor tracks; and

10 a schematic representation of the manufacturing steps of printed conductors by means of laser direct structuring on a base body according to embodiments of the invention.

Preferred embodiment of the invention

2 shows a schematic representation of an LED light 20 according to an embodiment of the invention. This has a support element 22 with a three-dimensionally structured surface 24 on. In particular, the surface comprises 24 two areas that are flat and enclose an angle that is different from 180 °. In these areas of the support element 22 Each are arranged a plurality of LEDs. In this example, the LEDs are arranged linearly, in particular in a direction of elongation of the carrier element 22 parallel to the y-axis of the in 2 shown coordinate system runs. However, the LEDs can also be distributed randomly or distributed arbitrarily on the support element. Furthermore, the LED light 20 a reflector 26 on, which is exemplified as a flat trained reflector, which also runs parallel to the y-axis.

By this arrangement can be in a particularly simple and advantageous manner in the photometric far field, a predeterminable light intensity distribution, such as Batwing, spot, etc., produce, without the need for expensive and complex-shaped optics or reflectors are required. Due to the three-dimensional design of the surface 24 the carrier element 22 , In particular with two areas, which may for example be flat, and enclose an angle with each other, can be used to generate a batwing light intensity distribution or other desired light intensity distribution a flat reflector 26 be used. Only in that the carrier element 22 With the LEDs having a three-dimensional structure, is an embodiment of the reflector 26 possible with such a simple geometry. The flat reflector 26 does not need to be deformed, rolled or pressed and its surface remains uninjured. So can the reflector 26 be designed much cheaper and at the same time, the reflectance of the reflector 26 increase. The reflector 26 may be, for example, aluminum with a highly reflective silver layer (Alanod Miro), in particular with a lacquer coating to protect the silver layer. This makes it possible the reflectance of the reflector 26 considerably increase. For example, the reflector 26 also have a diffusely reflecting white plastic film with a porous structure (porous PTFE (Zenit), PET (Furukawa film) or PP (White Optics film)). Due to the porous structure of this film also very high reflectance can be achieved. In particular, it is thus possible to achieve reflectivities which are more than 95%, in particular more than 98%. The desired radiation characteristic can be achieved, for example, by the angle of inclination of the areas of the surface 24 the carrier element 22 adjusted to each other, as well as by the inclination angle of these areas relative to the reflector 26 , In particular, the inclination of the reflector 26 the LED light 20 Also be variably adjustable to achieve a desired radiation characteristics. For example, to create a Batwing distribution, the reflector 26 be inclined by the angle α = 80 ° relative to the x-axis, a first region of the support element 22 by the angle β = 25 ° and a second region of the support element 22 around the angle γ = 75 °. With this arrangement results, for example, a Batwing light intensity distribution in the photometric far field as in 3 shown.

3 shows a schematic representation of a batwing light intensity distribution in the photometric far field of an LED light 20 with a flat reflector 26 according to an embodiment of the invention. Far field is to be understood as a distance from the light source that is large in relation to the extent of the light source. Depending on the specific design of the light source is the Far field condition fulfilled at a ratio of distance to extent of at least 10, in particular at least 100. The luminous intensity distribution curve is shown in a polar coordinate system, wherein the distance to the origin (intersection of the illustrated axes) is a measure of the luminous intensity. In particular, here is the light intensity distribution of an LED light 20 , as in 2 shown in a plane perpendicular to the y-axis of in 2 shown coordinate system shown. To produce such a light intensity distribution, according to one exemplary embodiment 32 LEDs with a luminous flux of 10 lumens each can be used, of which in the two areas of the surface 24 the carrier element 22 the LED light 20 each 16 LEDs are arranged linearly. Furthermore, it can be a flat, in particular Rechtecksförmiger reflector 26 be used with an extension in the direction of the y-axis of in 2 shown coordinate system of 12 cm. With such a light intensity distribution, a particularly homogeneous illumination of a flat surface is possible in an advantageous manner. The generation of such a light intensity distribution has been possible in the prior art only with great effort, especially only with complex optics or reflectors. A corresponding Batwing distribution according to the prior art is for comparison in 4 dargstellt.

4 shows a schematic representation of a luminous intensity distribution of a fluorescent lamp with a complex, in particular curved, reflector according to the prior art. The light intensity distribution is in turn shown in a polar coordinate system, wherein the distance from the origin is a measure of the light intensity. In particular, the values entered in the diagram indicate the luminous intensity in candela normalized to a luminous flux of 1000 lumens. The continuous luminous intensity distribution curve represents the luminous intensity distribution in a plane perpendicular to the longitudinal direction of the fluorescent lamp or to the luminaire axis and the dashed luminous intensity distribution curve shows the luminous intensity distribution in a plane along the luminaire axis. For comparison purposes, however, only the solid luminous intensity distribution curve is relevant, whose batwing distribution can only be achieved by a correspondingly complex design of the reflector of the fluorescent lamp. By comparing the two Batwing distributions 3 and 4 can be clearly seen that through the LED light 20 Batwing luminous intensity distribution generated in accordance with an embodiment of the invention 4 shown in no way inferior. Thus, it is already possible with a very simple design of a support element 22 , in this case with two mutually inclined planes, and a linear LED array using a plane reflector 26 produce substantially the same light intensity distribution as with a luminaire according to the prior art using complex and expensive ausgestalteter reflectors 26 ,

5 shows a schematic representation of an LED light 20 with a flat reflector 26 , which is designed according to an embodiment of the invention as a spot or spotlight. Again, in this embodiment, a plurality of LEDs are linear in two planar regions of the surface 24 a support element 22 arranged, which are inclined at an angle to each other or at different angles to a planar reflector 26 are inclined. In particular, the LED light can 20 according to an embodiment of the invention 64 Include LEDs with 10 lumens each. Furthermore, the reflector 26 square be formed with a side length of 12 cm. With reference to the in 2 shown coordinate system and the definition of the x and y axis used there and the inclination angles relative to the x-axis is in this arrangement, an inclination angle of the reflector 26 of α = 75 °, an inclination angle of a first area of the surface 24 the carrier element 22 of β = 10 ° and a tilt angle of a second area of the surface 24 the carrier element 22 of γ = 20 °. Furthermore, the arrangement shown is mirror-symmetrical to a mirror plane perpendicular to the x-axis. Also by this training of an LED light 20 can be generated with very simple means a specifiable light intensity distribution. In particular, by this embodiment, a light intensity distribution, as in 6 represented, are generated.

6 shows a schematic representation of a light intensity distribution in the far field of in 5 LED lamp shown as an embodiment of the invention 20 , The light intensity distribution is in turn in a plane which is perpendicular to the reflector plane, shown and in a polar coordinate system. As can be clearly seen, the design of the LED luminaire 20 according to 5 generate the light intensity distribution of a spotlight or spots. In particular, a narrow-angle emission characteristic with maximum axis light intensity can be achieved with little effort, in particular with a planar reflector 26 , realize.

So can already alone by different inclination of the areas of the areas of the surface 24 the carrier element 22 against each other and against the planar reflector 26 a variety of desired radiation characteristics, such as batwing, spot, etc. are generated.

Of course, three-dimensional reflectors can also be used in the preceding exemplary embodiments in order to provide, for example, even more diversity of possible emission characteristics or light intensity distributions.

7 shows a schematic representation of a carrier element 22 an LED light 20 according to an embodiment of the invention. This carrier element 22 has a three-dimensionally structured surface 24 in the form of two areas which enclose an angle with each other, wherein in these areas in each case a plurality of LEDs are arranged statistically distributed. This statistical distribution of LEDs on the surface 24 the carrier element 22 This prevents the formation of an image, eg in the form of stripes, and an excessively sharp cutoff angle on illuminated surfaces, which can improve the uniformity of the illuminance distribution on illuminated surfaces 22 also with a diffuse reflecting reflector 26 be combined. For example, the reflector 26 a diffusely reflecting white plastic film with a porous structure (porous PTFE (Zenit), PET (Furukawa film) or PP (White Optics film)). Furthermore, of course, reflective reflectors 26 with, for example, a highly reflective silver layer (Alanod Miro) with a carrier element 22 combined with statistically distributed LEDs. Thus, in a particularly advantageous manner additionally by the arrangement of the LEDs on the support element 22 , in particular linearly or statistically distributed, and the reflection properties of the reflector 26 , specular or diffuse, the emission characteristics are influenced in order to achieve a desired radiation behavior.

8th shows a schematic representation of a carrier element 22 whose surface 24 is formed in the form of two mutually inclined planes. In these two flat areas are each more tracks 28 with contact elements 30 arranged on which LEDs can be arranged. The LEDs can be used on these contact elements 30 glued or soldered on. Furthermore, the carrier element 22 as a basic body 32 be formed, on which the conductor tracks 28 are arranged. This basic body 32 is preferably formed as a partially metallized plastic body. The tracks 28 , Metallpads and / or vias can be generated by laser structuring or simple geometries by imprinting a structured metal foil. The carrier element 22 can also have a basic body 32 comprise, on the one or more printed circuit boards with a plurality of conductor tracks 28 are arranged. For example, it is also possible to glue a flexible printed circuit board on a correspondingly shaped metal part. In addition, the main body 32 be produced by extrusion or injection molding in any desired geometry, which in a particularly simple and cost-effective way LED lights 20 can be produced with a variety of ways the radiation characteristic regarding.

9a shows a schematic representation of a carrier element 22 an LED light 20 according to a further embodiment of the invention. In this case, the support element 22 as a basic body 32 formed with a three-dimensional surface structure. The main body 32 essentially has two areas that enclose an angle with each other. In particular, these areas of the body 32 almost at right angles to each other. In addition, the surface can 24 of the basic body 32 have further relief-like structures in the form of elevations and / or depressions in these areas. The basic body is preferred 32 is formed from a partially metallized plastic and can be produced for example by injection molding in any geometry. On this body 32 can then trace tracks 28 be generated, for example, according to a conductor track plan as in 9c shown. These tracks 28 can by means of laser direct structuring on the base body 32 be generated, resulting in a main body 32 with conductor tracks arranged thereon 28 , as in 9b shown, results. As a result, an LED array with a three-dimensional structure, based on the geometry of the body 32 or its surface 24 possible.

10 shows a schematic representation of the manufacturing steps of conductor tracks 28 by laser direct structuring on a base body 32 an LED light 20 according to embodiments of the invention. In step 34 becomes first a basic body 32 provided. The main body 32 is preferably made of a partially metallized thermoplastic. After a trace plan, the surface can be 24 of the basic body 32 by means of a laser beam 46 through surface activation 36 be structured, in particular by exposing and activating special active substances (additives) in the plastic. These active substances contain chemically inactive metal nuclei, which can only be activated by laser radiation. After a subsequent cleaning step 38 For example, the printed conductor structures can be metallized, in particular by copper plating 40 , Nickel-phosphorus plating 42 and gold plating 44 ,

Claims (9)

LED light ( 20 ) for generating a predefinable light intensity distribution in the photometric far field, comprising a carrier element ( 22 ), a plurality of on the support element ( 22 ) arranged LEDs, wherein the region of the carrier element ( 22 ) in which the LEDs are arranged as one Surface ( 24 ) of the carrier element ( 22 ), and a reflector ( 26 ), which in such a way with respect to the carrier element ( 22 ) is arranged, that light of the LEDs at least partially at the reflector ( 26 ) is reflective, characterized in that the surface ( 24 ) of the carrier element ( 22 ) has a three-dimensional structure. LED light ( 20 ) according to claim 1, characterized in that the reflector ( 26 ) is flat or three-dimensional. LED light ( 20 ) according to one of the preceding claims, characterized in that the reflector ( 26 ) has a reflective silver layer. LED light ( 20 ) according to one of the preceding claims, characterized in that the surface ( 24 ) of the carrier element ( 22 ) has at least two regions each approximable by a plane, the planes enclosing an angle other than 180 °. LED light ( 20 ) according to one of the preceding claims, characterized in that the carrier element ( 22 ) as basic body ( 32 ) with a plurality of interconnects ( 28 ) is trained. LED light ( 20 ) according to one of claims 1 to 4, characterized in that the carrier element ( 22 ) a basic body ( 32 ), on which at least one printed circuit board with a plurality of interconnects ( 28 ) is arranged. Method for producing an LED lamp ( 20 ) for generating a predefinable light intensity distribution with the steps: - producing a basic body ( 32 ) with a three-dimensional surface structure; - generating printed conductors ( 28 ) with a three-dimensional trace structure on the base body ( 32 ); Arranging LEDs on the tracks ( 28 ); and arranging a reflector ( 26 ) relative to the main body ( 32 ) at a predeterminable angle, so that light from the LEDs at least in part from the reflector ( 26 ) is reflected. Method according to claim 7, characterized in that the basic body ( 32 ) is produced by injection molding. Method according to claim 7, characterized in that the printed conductors ( 28 ) are generated by laser direct structuring.

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