EP2350523A2

EP2350523A2 - Led-based illumination body

Info

Publication number: EP2350523A2
Application number: EP09772011A
Authority: EP
Inventors: Jürgen Klaus; Johann Mitrowitsch; Sergey Kudaev
Original assignee: 2K Moxa Lighting GmbH
Current assignee: 2K Moxa Lighting GmbH
Priority date: 2008-07-03
Filing date: 2009-07-01
Publication date: 2011-08-03
Also published as: WO2010000241A3; DE112009002140A5; DE202008009797U1; WO2010000241A4; WO2010000241A2; DE102008031184A1

Abstract

The invention relates to an LED-based illumination body (1) comprising several modules (2), wherein each module (2) comprises an optical system (3) for receiving an LED carrier board (8) with at least one LED (5) arranged thereon, a reflector (6) and a light-transparent cover (4). The reflector (6) stretching over the light emitting cone of the LED (5) is provided with facets (6.1), wherein the individual facets (6.1) complement each other and form a closed, continuously extending optical functional surface and extend in such an angle to one another that the light emitted by the LED (5) is guided essentially via the facets (6.1) of the reflector (6) to the working plane of the light.

Description

LED-based lighting fixture

LED, the long time due to the low light output and d lack of availability of all light colors mainly only as Anzeelamf in seven-segment and dot matrix displays use, opens up more and more applications, such. B. in the lighting technology.

Due to the constantly advancing development of the LED, insbesonde by their cost-effective production and improve their «efficiency, these conventional bulbs, such as incandescent or halogen lamps solve and are for some time u. a. a LED bundles used in traffic control systems, in flashlights or headlamps of vehicles as mobile lighting or in LEI based televisions.

On the other hand, the use of the LED for LED-based lighting fixtures in street lighting installations appears problematic, since the LEDs, unlike the conventional lighting fixtures, do not emit the light on all sides but only on their light exit surface in the form of a narrow beam of light, which in conjunction with the interaction of a The reflector technology known from the beginning of the art with regard to a uniform distribution of light did not lead to any acceptable illumination of a large light useful surface.

The use of special mirrors, glass prisms or other lighting control systems also did not lead to a significant leap in quality due to the specific structure of the LED and the resulting lighting properties. In addition, LED-based street lighting concepts are previously known from the prior art, in which only a single reflector optics is used per LED module, the further beam shaping was moved to the central luminaire optics downstream of all modules. However, these solutions have the disadvantage that they are very costly, require a large amount of space and yet not illuminate the light field of use homogeneously.

US Pat. No. 7,090,370 B2 describes an LED-based lighting fixture which comprises a housing with an LED placed therein, a reflector and an exit surface which diffuses the light in a diffuse manner. The all LED commonly assigned central reflector here consists of a plurality of spaced apart individual reflectors. In this invention is a lighting fixture with a central luminaire optics, which has the aforementioned disadvantages.

From DE 100 21 725 A1 a faceted reflector is known, which contains a plurality of individual reflectors, which are embedded in a carrier. One main surface of the carrier represents the light entrance side, the other main surface the light exit side. The individual reflectors may be formed as cavities in the carrier, which preferably have a prismatic shape. The radiation to be reflected is totally reflected at a part of the cavity interfaces. On the entrance side of the faceted reflector, a light source in the form of one or more LEDs is placed. Thus, in this invention, the faceted reflector is shared by all LEDs.

In summary, it can be stated that there are currently no LED-based street lights available on the market that meet the requirements for energy saving and street lighting in accordance with applicable standardization. The object of the invention is now to propose an LED-based lighting fixture having a reflector optics suitable for achieving illuminance levels required for the street lighting devices, which generates a virtually homogeneous clearance profile on the Lichtwendzebene and which provides an efficient relationship between luminous flux and power used.

According to the invention, the LED-based lighting body comprises a plurality of modules, each of these modules each having an optical system for receiving an LED carrier board with at least one LED arranged thereon, a reflector and a light-transparent cover. The reflector spanning the light exit cone of the LED is embodied with facets, wherein the individual facets complement each other to form a closed, continuously extending optical functional surface and thus extend at a specific angle to each other such that the light emitted by the LED essentially passes over the facets of the reflector is directed to the light utility plane.

In a preferred embodiment of the invention, each of these modules is encapsulated in a gastight manner, several modules are encapsulated in groups gas-tight or it is formed the entirety of all modules gas-tight encapsulated. The encapsulations are either evacuated or filled with a noble gas with non-oxidative and / or non-corrosive action.

In each individual module, the entirety of the facets are formed by a reflector made in two parts, a first part being formed as a bridge overhanging the light exit cone of the LED at least partially, and the second part being formed by a base unit receiving the LED carrier board. In the assembled state of the two-part reflector, the respective outer facets of the bridge and the facets of the base unit contact each other without a gap.

In a particularly preferred embodiment of the invention, the light emitted by the LED light is directed exclusively and thus only indirectly via the facets of the reflector to the light utility plane. This is achieved by the reflector almost completely shields the LED in the relatively small area of its light exit surface.

The reflector spanning the light exit cone of the LED is sufficiently spaced from the light exit surface of the LED to form a gap, so that the light emitted by the LED in the region of the light exit surface of the LED can radiate unhindered and completely the reflector.

The reflector according to the invention is designed to generate a different beam shape from the light exit cone of the LED. In a particularly preferred embodiment of the invention, the bridge of the preferably two-part reflector has in cross-section substantially a double-T-shape with two opposing flanges and a web extending between the flanges. The two flanges and the web extending between the flanges each comprise a plurality of facets which extend in more than two planes to each other. To generate a preferably indirect light beam of the LED-based lighting fixture, the reflector extends over the LED or the LED carrier board such that the light exit cone of the LED is essentially spanned by its web.

In principle, it is possible, the reflector either completely made of a reflective material or from a reflector support with a to produce applied reflective coating. For cost reasons and for reasons of weight reduction would be in practice preferably use a reflector made of plastic reflector carrier, on the side facing the LED a reflector layer or mirror layer is brought to the facets.

The shape of the reflector, in particular its facets, has been determined in complex measuring and calculating methods with regard to their shape and size. The generated by the facets of the reflector on Lichtunterzebene clearance profile or the beam shape generated by the reflector has substantially a butterfly shape. Compared to the previously known from the prior art LED-based lighting fixtures are generated with the LED-based lighting fixture according to the invention almost homogeneous light spaces without dark areas; as without visible to the user Lichtwellenberge or valleys. This is particularly advantageous when homogeneously illuminated Lichtünzebenen are required.

The LED-based lighting fixture according to the invention can comprise a single module as well as a plurality of modules for the purpose of a higher illuminance. Regardless of the number of interconnected modules corresponds to the resulting common beam shape or the total light space profile substantially a butterfly shape, which is apparent on the Lichtwendzebene. According to the invention remains in training of a LED-based lighting fixture with multiple modules, in case of failure of one of these modules, the total light space profile generated by the remaining modules unchanged.

The optical system of the LED-based lighting body is preferably arranged within a base unit, which is designed to receive an LED carrier board with the LED arranged thereon and the reflector. For targeted and better heat dissipation, the optical System comprise a on the back of the LED carrier board, respectively the side facing away from the LED side of the LED carrier board, arranged Wärmeleitschicht. This heat conducting layer is preferably formed as a heat conducting foil in the form of a metal foil.

The LED-based lighting fixture is designed for both indoor and outdoor lighting applications. In order to avoid dirt deposits and aging phenomena, the module constructed from the optical system and the light-transparent cover is gas-tightly encapsulated.

If, as already mentioned, several modules are used within an LED-based lighting fixture, they are preferably arranged in a matrix-like manner in columns and rows to one another and connected to one another.

For switching on and off of individual modules, groups of modules or the totality of all modules, a control or regulating device is provided. Furthermore, the LED-based lighting body according to the invention may comprise a plurality of sensors which are used to save energy, to adapt to different lighting conditions and to implement user wishes, for example for switching on and off. These sensors are designed as sensors for color control and / or for personal identification and / or brightness control and coupled to the controller or control. It has been found to be particularly advantageous if, for example, the illuminance and / or illumination color of the LED weather-dependent and user-dependent using these aforementioned sensors and the control / control are controllable. Furthermore, the LED of each module has contrast-altering properties, which significantly increases the performance and performance of the new LED-based lighting fixture.

A suitable field of application of the LED-based lighting fixture is the street and court lighting, in which homogeneously illuminated Lichtünzebenen without dark spots not only desired, but are also required by law. Depending on the illumination height of the LED-based lighting fixture used for street lighting, its number of modules may be either variable or, if the number of modules is unchanged, the terminal voltage of the modules adapted accordingly, ie. H. increased or decreased. Furthermore, it is possible to control modules only in groups.

A particularly preferred embodiment of such an LED-based lighting fixture for street lamps has an elliptical shape in cross section, wherein a plurality of elliptical elements placed one above the other together form the housing provided for receiving a plurality of modules. For this purpose, smaller and larger elliptical elements are arranged alternately in cross-section, wherein the larger in cross section and outwardly projecting elements are used for optimal heat dissipation. The preferably made of aluminum and the housing of the street lamp forming ellipses have only a very low construction height in a range between 7cm and 15 cm. This extremely flat design is achieved using the particularly space-saving reflection optics of the LED-based lighting fixture according to the invention. The beam shaping of the emitted light takes place in each case in the modules by means of the reflector. A beam forming downstream of the respective modules together for all modules by means of a central luminaire optics is no longer necessary according to the invention. The significant advantages and features of the invention over the prior art are essentially:

^■ of modular construction of the LED-based lighting fixture, wherein each of each of the modules comprises an optical system for receiving an LED mounting board having at least one LED mounted thereon, a reflector and a light-transparent cover,

^■ by using a specially shaped and multi-faceted LED-spanning reflector, the light emitted by the LED is directed essentially to the light utility plane via the facets of the reflector,

^■ substantially double-T-shaped in cross-section bridge of the two-piece reflector generates a different from the light exit cone of the LED beam shape,

^■ the reflector generated by the beam shape has a substantially butterfly shape or produced on the working plane of light, a butterfly-like design in cross-section clearance profile,

^■ the modular design of the LED-based lighting fixture significantly reduces redundancy and downtime,

^■ by forming the LED-based lighting fixture with several modules, in case of defect of one or several of these modules, the total light-space profile generated by the remaining modules remains unchanged,

^■ every single module, several modules summarized in groups or the entirety of the modules are gas-tight encapsulated, whereby the luminosity reducing Ab- and Deposits and the aging processes are avoided and a modular interchangeability is made possible

^{■ By} means of the LED, which can be used for street lighting for the first time, with its technical lighting properties, a harmony between the power used and the available luminous flux is achieved.

^■ The LED-based lighting fixture, which was developed especially for street lighting, ensures a long service life and significantly reduces maintenance intervals.

^■ the illuminance of the LED-based lighting fixture can easily be varied using control / regulation by switching individual modules or groups of modules on or off or by adapting the supply voltage, and

^■ The LED-based lighting fixture can be mounted safely and easily by a user.

The objectives and advantages of this invention will become better understood and appreciated after a careful study of the following detailed description of the preferred non-limiting example embodiments of the invention herein, together with the accompanying drawings, in which:

Fig. 1: an exploded view of the LED-based

Lighting fixture,

Fig. 2: the reflector in a perspective view from above and

Fig. 3: the reflector in a further perspective view, laterally.

1 shows an exploded view of the LED-based lighting fixture 1 according to the invention. The LED lighting fixture 1 consists from several modules, but only a single module 2 is shown as an example. The module 2 consists of an optical system 3 and a light transparent cover 4 with a transmittance of about 70%, preferably an anti-reflective glass. The optical system 3 and its transparent cover 4 are fixedly connected to each other for the purpose of forming a gas-tight capsule using a gasket shown by a dashed line. For assembly reasons, has proven particularly advantageous when the optical system 3 is placed within a preferably metallic base unit 10, as shown. The optical system 3 comprises a yellow LED 5 and a two-part reflector 6 with facets 6.1 according to FIGS. 2 and 3, spanning the light exit cone of the LED 5, which extend at a specific angle to one another such that the light emitted by the LED 5 is exclusively and thus only indirectly via the facets 6.1 of the reflector 6 reaches the Lichtwendzebene. The essentially double-T-shaped cross-section of the reflector 6 is constructed here from a reflector carrier made of plastic with a reflective coating applied thereto. Within the base unit 10, an LED support board 8 for receiving the LED 5 arranged thereon and the reflector 6 is further arranged. At the rear side of the LED carrier board 8, respectively the side of the LED carrier board 8 facing away from the LED 5, a heat-conducting layer provided for the purpose of better heat dissipation is placed in the form of a heat-conducting foil consisting of copper or aluminum.

Figures 2 and 3 show one and the same reflector 6 according to the invention in a detailed perspective view from above and a lateral perspective view. The essentially cross-sectionally double-T-shaped bridge of the reflector 6 corresponds to an irregularly shaped, but symmetrically shaped body with two flanges 6.2 and a web 6.3. The length is about 50 mm, the width about 40 mm and the height only 21 mm. The effectively available reflection surface is 7.5 x 10.1 mm ² . The symmetry axis of the reflector 6 extends orthogonally to the light axis in the direction of the longitudinal axis of the web 6.3. The two opposing flanges 6.2 and 6.3 extending between the flanges 6.3 comprise each of the LED 5 facing facets 6.1, in the illustrated example, the light exit cone of the LED 5 is completely spanned by the web 6.3 of the reflector 6. The individual facets 6.1 extend in such a way at a certain angle to one another that the light emitted by the LED 5 reaches the light utilization plane only indirectly via the facets 6.1 of the reflector 6. As can be seen by the viewer, the web 6.3 of the reflector 6 tapers from its upper side to the bottom side facing the LED. The facets 6.1 are formed as an octagon of different sizes, and extend from the top of the reflector 6 to the wedge-shaped bottom of the reflector 6. Between the bottom of the reflector 6 and arranged on an LED support board 8 LED 5 is a gap 7 is formed, so that the light emitted by the LED 5 light can illuminate unhindered all facets 6.1 of the reflector 6. By means of the facets 6, a beam shape is generated which is different from the beam shape of the light exit cone of the LED 5. The generated on the light utility plane clearance profile or the beam shape substantially corresponds to a butterfly shape with almost homogeneous light space fields without dark spots.

In an unillustrated matrix-like arrangement of 20 modules 2 with an array of 4 x 5 modules for use as an LED-based street lighting an electrical connection power of 100 watts is needed. The illuminance provided by all the modules 2 together amounts to 10 lx, as a result of which an LED-based lighting body 1 placed at an illumination height of 8 m can homogeneously illuminate a light utility plane with an area of approximately 40 × 7.5 m ² . LIST OF REFERENCE SIGNS

1 LED-based lighting fixture

2 module

3 optical system

4 cover

5 LEDs

6 reflector

6.1 facet

6.2 Flange

6.3 Footbridge

7 gap

8 LED carrier board

9 heat conducting layer

10 base unit

11 seal

Claims

1. LED-based lighting fixture (1) comprising a plurality of modules (2), each of these modules (2) each having an optical system (3) for receiving an LED support board (8) with at least one LED (5) arranged thereon, a reflector (6) and a light transparent cover (4), and of the light exit cone of the LED (5) spanning reflector (6) with facets (6.1) is formed, wherein the individual facets (6.1) to a closed, continuously extending complement optical functional surface and thereby extend at a certain angle to each other so that the light emitted by the LED (5) light is directed substantially over the facets (6.1) of the reflector (6) to the Lichtwendzebene.

2. LED-based lighting fixture (1) according to claim 1, characterized in that

a. each of these modules is gas-tight or encapsulated

b. several modules in groups gas-tight or encapsulated

c. the entirety of all modules are formed gas-tight encapsulated,

wherein the encapsulations are either evacuated or filled with a noble gas having a non-oxidative and / or non-corrosive action.

3. LED-based lighting fixture (1) according to claim 1 or 2, characterized in that in each individual module, the totality of the facets by a two-piece reflector are formed, wherein a first part as a light exit cone of the LED (5) at least partially spanning bridge and the second part is formed by a LED carrier board receiving base unit.

4. LED-based lighting fixture (1) according to claim 3, characterized in that in the assembled state of the two-piece reflector (6) the respective outer facets (6.1) of the bridge and the facets (6.1) of the base unit (10) contact each other without a gap ,

5. LED-based lighting fixture (1) according to one of claims 1 to 4, characterized in that the light emitted by the LED (5) exclusively and thus only indirectly through the facets (6.1) of the reflector (6) is directed to Lichtwendzebene ,

6. LED-based lighting fixture (1) according to one of claims 1 to 5, characterized in that the light exit cone of the LED (5) spanning reflector (6) to form a gap (7) sufficiently from the light exit surface of the LED (5) is spaced.

7. LED-based lighting fixture (1) according to any one of claims 1 to 6, characterized in that the reflector (6) is designed to generate a beam shape that is different from the beam shape of the light exit cone of the LED (5).

8. LED-based lighting fixture (1) according to one of claims 1 to 7, characterized in that the light space profile generated on the Lichtwendzebene or the beam shape substantially one Butterfly shape with nearly homogeneous light space fields without dark spots corresponds.

9. LED-based lighting fixture (1) according to one of claims 1 to 8, characterized in that both the beam shape of each individual module (2) as well as from the interconnection of several modules (2) resulting common beam shape and the overall light space profile substantially corresponds to a butterfly shape.

10. LED-based lighting fixture (1) according to one of claims 1 to 9, characterized in that the bridge of the reflector (6) in cross-section substantially double-T-shaped, wherein the two flanges (6.2) and between the flanges (6.2) extending web (6.3) each comprise facets (6.1), and the light exit cone of the LED (5) is substantially spanned by the web (6.3) of the reflector (6).

11. LED-based lighting fixture (1) according to any one of claims 1 to 10, characterized in that the reflector (6) consists either completely of a reflective material or of a reflector support with a reflective coating applied thereto.

12. LED-based lighting fixture (1) according to one of claims 1 to 11, characterized in that the optical system (3) on the rear side of the LED support board (8), respectively, the LED (5) facing away from the LED Carrier board (8), arranged Wärmeleitschicht (9).

13. LED-based lighting fixture (1) according to one of claims 1 to 12, characterized in that when forming an LED-based lighting fixture (1) with a plurality of modules (2) in case of failure of one or more of these modules (2), of the remaining modules (2) generated total light space profile remains unchanged.

14. LED-based lighting fixture (1) according to any one of claims 1 to 13, characterized in that a control or regulating device provided to modules (2) individually, in groups or their entirety to turn on or off.

15. LED-based lighting fixture (1) according to one of claims 1 to 14, characterized in that sensors are provided for color control and / or personal identification and / or brightness control, which are coupled to the controller or controller.

16. LED-based lighting fixture (1) according to one of claims 1 to 15, characterized in that the illuminance and / or illumination color of the LED (5) is weather-dependent or user-dependent using sensors and the controller / controller controllable.

17. LED-based lighting fixture (1) according to one of claims 1 to 16, characterized in that the LEDs used (5) have contrast-changing properties.

18. LED-based lighting fixture (1) according to one of claims 1 to 17, characterized in that the LED-based lighting fixture (1) is used for street lights or square lighting, wherein the number depending on the lighting height the modules (2) used for the LED-based lighting fixture (1) is either variable or, in the case of an unchanged number of modules, the terminal voltage of the modules (2) is adapted accordingly, ie increased or decreased.