EP2748527B1 - Light source device - Google Patents

Description

Technical area

The present invention relates to a light source device comprising at least one LED having a light emission side and a rear side facing the light emission side, wherein the at least one LED is arranged on a circuit board, at least one main heat sink, which is coupled to the back of the at least one LED, and a drive device for Operating the at least one LED, the driver device having at least one connector for coupling to a power supply. It also relates to a light source device having at least one LED with a Lichtabstrahlseite and the light emitting side opposite back, wherein the at least one LED is arranged on a circuit board, wherein the board is defined by an arrangement level of at least one LED, at least one main heat sink, with the Rear side of the at least one LED is coupled, wherein the main heat sink has a lateral surface, and a driving device for operating the at least one LED, wherein the driving device has at least one terminal for coupling to a power supply.

State of the art

Generic light source devices are used for example as construction site lights. A well-known from the prior art construction site light 30 is in Fig. 1 shown. This comprises an array 34 covered by a glass pane 32 with a multiplicity of LEDs. A shock protection 36 surrounds the combination of LED array 34 and glass pane 32. On the back of a non-illustrated main heat sink for cooling the LEDs of the LED array 34 is provided. Furthermore, a swivel arm 38 is provided at the back, by means of which the construction site lamp 30 can be set up in the operating state for illuminating an object with a fixed emission direction.

A disadvantage of the construction site luminaire known from the prior art is that only LEDs with a limited power can be used, since otherwise a permissible operating temperature is exceeded, which would lead to damage to the construction site luminaire. Another disadvantage is that in the known construction site light only two beam angles can be realized, once with erected site light 30 by means of the folded pivot arm 38 and the other with flat placed on a surface construction site light 30. Especially when using the swing arm, the arrangement is relatively unstable against wind or vibrations, as they are commonly found on construction sites.

EP 2309168 . WO 2011/054092 and US 2003/0039118 describe light source devices of the prior art.

Presentation of the invention

The object of the present invention according to a first aspect is therefore to develop a light source device of the type mentioned in such a way that a higher emission power is made possible.

This object is achieved by a light source device having the features of patent claim 1.

The present invention according to the first aspect is based on the finding that a higher emission power is made possible when measures are taken to improve the cooling capacity, that is to say the dissipation of heat resulting from power loss. According to the invention it is therefore provided that the light source device further comprises a front heat sink, which is thermally coupled to the main heat sink. The additional use of a front heat sink, the effective cooling capacity can be significantly increased, so that more powerful LEDs or larger numbers of LEDs can be used. This results in a significant increase in the light emission.

The front cooling body preferably has an emission surface which is not coupled to the main cooling body, the front cooling body being arranged such that the emission surface is oriented toward the light emission side of the at least one LED. "Not coupled to the main heat sink" means here that the front heat sink has a rear surface which is opposite its emission surface and which is thermally coupled to the main heat sink. In this way, almost the entire surface of the light source device can be used for cooling purposes, thereby enabling maximum radiation performance without active cooling measures such as a blower and the like. The board is preferably coupled via a thermal interface material with the main heat sink, wherein the thermal interface material is particularly elastic. A special preferred thermal interface material is available under the name T-flex Laird. By such a coupling unevenness of the heat sink can be compensated. This means that their surfaces do not need to be milled so that cheaper heatsinks can be used. Accordingly, it can be provided that the front heat sink is coupled via a thermal interface material with the main heat sink, wherein also here preferably the thermal interface material is elastic. In addition to the already mentioned aspect of balancing unevenness of the heat sink or the circuit board thereby the substrate is connected to the main heat sink and achieved a seal against moisture. This reduces the risk of moisture ingress between heatsinks without the need for additional measures. Instead of using a single board, the invention can also be implemented with a variety of boards.

The main heat sink has a circumferential impact protection device, in particular made of plastic. In this way, regardless of which light emission direction is selected, the light source device is reliably protected against damage by an uneven ground and the like, since the impact protection device ensures a certain distance. At the same time, the substrate on which the light source device stands is protected against damage due to excessive temperatures. In particular, the circumferential impact protection device may also be present in the present invention according to the second aspect.

It is particularly advantageous if the impact protection device has a first component contacting the main and front heat sinks and a second component forming the outer surface of the impact protection device, wherein the first component consists of a more elastic material than the second component. In this way, manufacturing tolerances can be compensated. In addition, the fixation between the heat sinks can be ensured thereby.

Further preferably, a handle is formed in the impact protection device, which serves for easy transport of the light source device. In addition, the handle allows positioning of the light source device, without the possibly heated heat sinks would have to be touched. Preferably, the handle is not centrally placed due to the asymmetric weight distribution due to the different angles of attack of the above-mentioned partial surfaces. In particular, the handle can also represent an advantageous embodiment according to the second aspect of the invention.

At least one coupling device for mechanically and / or electrically coupling a plurality of light source devices may be arranged in the impact protection device. Such coupling devices can be used to couple any number of light source devices to achieve a desired brightness. Only one of these coupled light source devices needs to be coupled to a power supply.

Finally, it is preferred if the driver device is mounted on the side of the main heat sink, which is not coupled to the front heat sink. As a result, the driver device is largely thermally decoupled from the LEDs, which results in an increase in the service life of the components of the driver device and thus of the light source device.

The light source device may further comprise a channel in which connection lines connecting the circuit board to the driver device are arranged. It can be provided that in the channel at least one gradation is formed such that thereby the distance between the current-carrying areas of the board and the main heat sink is increased. In this way, a voltage flashover between current-carrying areas of the board and the main heat sink can be reliably prevented, resulting in increased security for a user of the light source device.

For the same purpose may be provided in the region of the channel a recess in the main heat sink, which is designed such that thereby the distance between the current-carrying areas of the board and the main heat sink is increased.

The light source device may further comprise a moisture-permeable membrane, in particular a Goretex membrane, which is arranged such that moisture present in cavities of the light source device can escape from the light source device. In this way, damage to the light source device by water ingress is reliably avoided.

Furthermore, a sealing ring and a transparent pane arranged above the at least one LED can be provided, wherein the sealing ring is arranged between the pane and the front cooling body. As a result, the disc, the front heat sink, the thermal interface material and the main heat sink are fixed against each other. Moreover, the entry of moisture is prevented.

According to a second aspect of the present invention, the object is to develop a generic light source device of the initially mentioned type such that different radiation directions are made possible in a simple manner with high stability.

The embodiments described above in connection with the present invention according to the first aspect also apply mutatis mutandis to the present invention according to the second aspect and vice versa. Further, it is to be understood that the embodiments, aspects and features described in the first and second aspects of the present invention are not mutually exclusive, but that one or more of the embodiments, aspects or features described herein may be each one or more of those described herein Embodiments, embodiments or features can be combined.

The object according to this second aspect is achieved by a light source device having at least one LED with a light emission side and one of the light emission side opposite rear side, wherein the at least one LED is arranged on a circuit board, wherein by the board an assembly plane of the at least one LED is defined, at least one main heat sink, which is coupled to the back of the at least one LED, wherein the main heat sink has a lateral surface and a A driver device for operating the at least one LED, the driver device having at least one connector for coupling to a power supply. The lateral surface of the main cooling body has at least a first, a second, a third and a fourth partial surface, wherein the first partial surface extends parallel to the arrangement plane, wherein the second partial surface encloses a first angle to the first partial surface, wherein the third partial surface forms a second angle to the first Partial surface (25a) includes and wherein the fourth partial surface includes a third angle to the first partial surface, wherein at least two of the angles are different.

The present invention is based on the finding that different emission directions can be set particularly stable if the main heat sink itself is used for this purpose. According to the invention therefore, the lateral surface of the main heat sink at least a first, a second, a third and a fourth partial surface, wherein the first partial surface is parallel to the arrangement plane of the at least one LED, wherein the second partial surface includes a first angle to the first partial surface, wherein the third Partial surface includes a second angle to the first partial surface and wherein the fourth partial surface includes a third angle to the first partial surface, wherein at least two of the angles are different are. In this way, a hinged element, as known from the prior art, can be avoided, in which there is a risk that it collapses due to the influence of wind or vibrations or can not prevent the construction site lamp from falling over.

Particularly preferably, the first, the second and the third angle are different from each other, so that at least three different radiation directions can be realized. In a preferred embodiment, the lateral surface further comprises a fifth partial surface which encloses a fourth angle to the first partial surface. In this way, even four different radiation directions can be realized. Particularly preferably, the lateral surface has a further partial surface which extends parallel to the first partial surface, the second, the third and the fourth partial surface or the second, the third, the fourth and the fifth partial surface being arranged between the first and the further partial surface. The main heat sink thus has the shape of an irregularly shaped truncated pyramid. Due to the additional partial surface, a radiation direction can be realized vertically upwards.

Preferably, the main heat sink on a plurality of fins, which are arranged projecting from the first part surface. By forming the length and height of the respective fins, the respective partial surfaces of the main cooling body are thereby realized. In a particularly preferred embodiment, the fins extend radially. In this way, it is ensured that, regardless of on which partial surface the light source device is stored, a chimney is formed by the heated air can be emitted as a result of convection. In other words, such a configuration of the fins of the main heat sink allows a flow of the heated air from the bottom up regardless of the position of the light source device. As a result, satisfactory cooling results can be achieved regardless of the location of the construction site luminaire.

Preferably, the main heat sink has a recess, wherein the fins extend radially to this recess. The recess ensures that there is no constriction due to the radially inwardly extending fins, which would prevent convection.

Preferably, the recess is arranged where the second, the third and the fourth or the second, the third, the fourth and the fifth partial surface would converge without the recess. In this way, the chimney effect is enabled in all layers of the light source device.

Preferably, each fin has an outer end and an inner end oriented towards the center of the main cooling body, wherein the inner ends of adjacent fins have a predeterminable minimum distance. As a result, the chimney effect can be ensured to a predeterminable extent.

Preferably, the predetermined minimum distance is set by varying the length of the respective fins. In other words, therefore, the individual fins have different lengths in their extension to the recess.

It may be provided that the connection for coupling with the at least one power supply is designed to be pivotable. As a result, the light source device can be coupled to a power supply independently of its instantaneous position in such a way that the connection is exposed to the least possible bending or shearing forces.

Further preferred embodiments emerge from the subclaims.

Short description of the drawing (s)

Fig. 1

in schematischer Darstellung eine aus dem Stand der Technik bekannte Lichtquellenvorrichtung mit einem LED-Array;

Fig. 2

verschiedene schematische Darstellungen eines ersten Ausführungsbeispiels einer erfindungsgemäßen Lichtquellenvorrichtung;

Fig. 3

weitere Ansichten des in Fig. 2 dargestellten Ausführungsbeispiels einer erfindungsgemäßen Lichtquellenvorrichtung;

Fig. 4

eine Explosionsdarstellung der in der Fig. 2 und der Fig. 3 gezeigten Lichtquellenvorrichtung;

Fig. 5

verschiedene Darstellungen eines zweiten Ausführungsbeispiels einer erfindungsgemäßen Lichtquellenvorrichtung;

Fig. 6

verschiedene Darstellungen eines dritten Ausführungsbeispiels einer erfindungsgemäßen Lichtquellenvorrichtung; und

Fig. 7

verschiedene Darstellungen des bei der in Fig. 6 dargestellten Ausführungsform einer erfindungsgemäßen Lichtquellenvorrichtung verwendeten Hauptkühlkörpers.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Show it:

Fig. 1

a schematic representation of a known from the prior art light source device with an LED array;

Fig. 2

various schematic representations of a first embodiment of a light source device according to the invention;

Fig. 3

further views of the in Fig. 2 illustrated embodiment of a light source device according to the invention;

Fig. 4

an exploded view of the in the Fig. 2 and the Fig. 3 shown light source device;

Fig. 5

different representations of a second embodiment of a light source device according to the invention;

Fig. 6

different representations of a third embodiment of a light source device according to the invention; and

Fig. 7

various representations of the at Fig. 6 illustrated embodiment of a light source device according to the invention used main heat sink.

Preferred embodiment of the invention

In the following embodiments, the same reference numerals are used for the same and equivalent components of the various embodiments. These are introduced only once for the sake of clarity.

The FIGS. 2 to 4 show various schematic representations of a first embodiment of a light source device according to the invention.

Behind an array with a plurality of LEDs 1, a main heat sink 2 is arranged. A front heat sink is designated 3. The main heat sink 2 has a lateral surface which corresponds to an irregular truncated pyramid. Its lateral surface has a plurality of partial surfaces 25a to 25f, wherein the first partial surface 25a is oriented parallel to the arrangement plane of the LEDs 1. The second partial surface 25b encloses an angle of 85 ° to the first partial surface 25a, the third partial surface 25c an angle of 70 °, the fourth partial surface 25d an angle of 50 °, the fifth partial surface 25e an angle of 30 °. The sixth partial surface 25f runs parallel to the first partial surface 25a. The specified angles are merely exemplary and may vary depending on the application. Due to the different angles, the light source device can be positioned in different positions relative to a base, so that in this way the emission direction of the LEDs 1 is likewise varied. To thermally separate a driver device 5 from the LEDs 1, it is located on the side facing away from the LEDs side of the main heat sink 2. The main heat sink 2 has a plurality of fins 6, whereby the contact surfaces to the housing 7, 8 of the driver device 5 and thus the Heat transfer is kept low. In the housing 7, 8 of the driver device 5 is also located to place on the back of the connection to the power supply (not shown). This is preferably designed to be pivotable in order to take into account the different positions in which a light source device according to the invention can be arranged relative to a base.

The housing 7, 8 of the driver device 5 and a circumferential impact protection 9 prevent the main heat sink 2 can come into direct contact with the pad. This allows air to flow into the fins 6 and prevents damage to the main heat sink 2.

A handle 10, which is part of the impact protection 9 and is not centrally located due to the asymmetrical weight distribution, allows positioning of the light source device without touching the heated heat sinks 2, 3.

The light source device can be constructed according to various security classes. So can from the Driver device 5 is already provided a touchable supply voltage. However, it is also the LED substrate, that is, the board 11, insulated so that the relevant regulations are met. This can be done for example by means of ceramic or even using FR4 boards. Instead of a circuit board 11 shown in the embodiment, a plurality of individual boards can be used.

In the embodiment shown in the figures, a double insulation is ensured by using a FR4 board and an underlying thermal interface material (TIM) 12. The LEDs 1, in this case, single LEDs are used, but also multi-chip LEDs are used, are applied to the substrate 11, which in turn is connected via the TIM 12 to the main heat sink 2. The waste heat of the LEDs 1 is derived in this way in the main heat sink 2. Likewise, in turn, the front heat sink 3 is thermally connected via the TIM 12.

In order to ensure the connection of the two heat sink 2, 3, they are firmly connected to each other, in this case by means of a screw 13. Due to this fixation results for both the circumferential impact protection 9 as well as for the internal construction a defined distance in which positions the components Need to become. To take account of manufacturing tolerances find here elastic components application.

The TIM 12 takes on a significant part of the adaptation. In addition, the TIM 12 takes over the connection of the circuit board 11 to the main heat sink 2 and the connection Both heat sink 2, 3 and the task of sealing against moisture.

To compensate for manufacturing tolerances of the shock protection 9 is made of two different plastics, a solid and an elastic. The elastic part ensures the fixation between the heat sinks 2, 3. In this case, small tips can be provided on the heat sinks 2, 3, which drill into the impact protection 9, or small tips on the impact protection, which bend during fixation.

The fixation of the components with respect to the inner elements of the light source device is fulfilled by a sealing ring 15, which is arranged between the front cooling body 3 and a transparent plate 14. The sealing ring 15 fixes the disc 14, a spacer 16 and the board, that is, the substrate 11, between the heat sinks 2, 3. The sealing ring 15 also prevents the entry of moisture at this point.

The spacer 16 positions the disc 14 and prevents contact with the front heat sink 3, which is particularly important when using glass for the disc 14. Between the disc 14 and the spacer 16, further elements with optical properties, such as lenses, reflectors and the like may be arranged.

Connecting lines between the driver device 5 and the substrate 11 with the LEDs 1 extend in a plastic channel 17. This channel 17 projects through the main heat sink 2, the TIM 12 and the substrate 11 into one Cavity below the spacer 16. If the front heat sink 3 protrude beyond the spacer 16, the spacer 16 would ensure the insulation to the heat sink 3. In this cavity, the lines are connected to the substrate 11.

If safety distances are required at this point, 17 steps 18 can be introduced into the channel, which ensure these distances. Alternatively or additionally, a recess 19 may be provided in the heat sink 2 to ensure these distances.

In order to ensure the tightness at this point, a further sealing ring can be applied to the channel 17. In order to ensure the escape of moisture, at any point a moisture-permeable membrane, in particular a Goretex membrane, are introduced.

Fig. 5 shows a second embodiment of a light source device according to the invention. In this case, the spacer 16 and the shock protection 9 is united in one part. The space for the connection of the LEDs 1 is located under a cover 20, which is also part of the element 9, 16.

The terminal 21 to a power supply is made pivotable, whereby the light source device can also be placed on the back.

In the impact protection 9 lateral coupling devices 22 may be provided, which allow a coupling of multiple light source devices with each other.

In Fig. 6 a third embodiment of a light source device according to the invention is shown, in which the main heat sink 2, see Fig. 7 , Is carried out particularly advantageous. How very clear Fig. 7 can be removed, the fins 6 extend radially to a recess 23. The recess 23 is arranged where these partial surfaces 25b, 25c, 25d, 25e would converge without recess. Each fin 6 has an outer and an inner end oriented toward the center of the main heat sink 2, the inner ends of adjacent fins 6 having a predeterminable minimum distance. This predetermined minimum distance is set by varying the length of the respective fins 6. In this embodiment, regardless of the position of the light source device a chimney effect is achieved, whereby a particularly high cooling capacity is made possible in all layers of the light source device.

Claims (9)

1. Light source device having

   - at least one LED (1) with a light emitting side and a rear side opposite the light emitting side, the at least one LED (1) being arranged on a circuit board (11) ;

   - at least one main heat sink (2), which is coupled to the rear side of the at least one LED (1); and

   - a driver device (5) for driving the at least one LED (1), the driver device (5) having at least one connection (21) for coupling to a power supply;

   the light source device further comprising a front heat sink (3), which is thermally coupled to the main heat sink (2),
   characterized in that
   the main heat sink (2) has a circumferential shock prevention device (9), in particular made of plastic.
2. Light source device according to Claim 1,
   characterized in that
   the shock prevention device (9) has a first component, making contact with the main heat sink (2) and the front heat sink (3), and a second component, forming the outer surface of the shock prevention device (9), the first component consisting of a more resilient material than the second component.
3. Light source device according to either of Claims 1 and 2, characterized in that
   a handle (10) is formed in the shock prevention device (9).
4. Light source device according to one of Claims 1 to 3, characterized in that
   at least one coupling device (22) for coupling a plurality of light source devices mechanically and/or electrically is arranged in the shock prevention device (9).
5. Light source device according to one of the preceding claims,
   characterized in that
   the front heat sink (3) has a radiating surface not coupled to the main heat sink (2), the front heat sink (3) being arranged in such a way that the radiating surface is oriented towards the light emitting side of the at least one LED (1).
6. Light source device according to one of the preceding claims,
   characterized in that
   the circuit board (11) is coupled to the main heat sink (2) via a thermal interface material (12) which is in particular formed so as to be resilient.
7. Light source device according to one of the preceding claims,
   characterized in that
   the front heat sink (3) is coupled to the main heat sink (2) via a thermal interface material0020(12) which is in particular formed so as to be resilient.
8. Light source device according to one of the preceding claims,
   characterized in that
   the driver device (5) is fitted to the side of the main heat sink (2) that is not coupled to the front heat sink (3).
9. Light source device according to one of the preceding claims,
   characterized in that
   it further comprises a channel (17) in which connecting leads which connect the circuit board (11) to the driver device (5) are arranged.

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