EP2376829B1 - Led-based lighting system - Google Patents

Description

The present invention relates to a lighting fixture for exterior lighting with at least one light emitting diode array and a housing, wherein the light emitting diode array comprises a plurality of light emitting diodes which are surface mounted on a single carrier, the light emitting diodes having a diode element and an associated element with a luminophore, wherein the diode element and the element associated therewith are arranged such that the light generated by the diode element during operation excites the luminophore, the light emitting diode array being disposed in the housing, the housing being terminated and having a substantially transparent portion and having one therein Housing arranged heat conducting element, wherein the carrier of the light emitting diode array is thermally conductively connected to a mounting portion of the heat conducting element. Exterior lighting can be used, for example, for roads, parking lots, parking garages, tunnels and underpasses, mines, parks, gardens, sidewalks, squares and more generally in the area outside of buildings.

In the outdoor lighting today mainly sodium lamps, mercury vapor lamps and so-called energy-saving lamps are used. The large number of lighting fixtures causes a considerable energy consumption. It is therefore desirable to use more efficient lighting techniques. These include, among other things, the light-emitting diode technology, which has a good efficiency and whose light can be aligned relatively easily, so that the energy used can be optimally used. In addition, LEDs are dimmable, which allows further savings by adjusting the brightness. Another advantage is the fast turn-on and turn-off without warm-up times. It is also advantageous that the color of the light can be easily selected by using different diodes. Also, the generation of white light is possible by the actually colored light of a light emitting diode, which may even have a narrow spectral bandwidth, is converted with a luminophore into other wavelengths. The luminophore is illuminated with either a blue or an ultraviolet light emitting diode and converts the irradiation wavelengths by luminescence into longer wavelengths. With a suitable choice of the luminophore produces white light. Suitable materials for the luminophore are, for example, yttrium-aluminum-garnet (YAG) doped with cerium or a novel material containing an alkaline-earth orthosilicate and preferably activated with europium. The latter material is in the EP 1 347 517 described. Alternatively, red, green and blue LEDs can also be used in light-emitting diodes whose interaction produces white light.

A light-emitting diode can have different emission characteristics. The chip of a light emitting diode first radiates in all directions in its environment. Typically, reflectors are placed around the chip to focus the light in a preferred direction. The slightly collimated light in this case then falls, if it is a colored light emitting diode, generally on a plastic lens, which defines an opening angle.

The opening angle of a light-emitting diode describes the angular range over which the light exits the light-emitting diode. Outside the opening angle, the light emitting diode emits no light. If it is a white light LED, the luminophore can be arranged between the chip and the plastic lens. This performs the conversion of the light color before the light leaves the LED through the lens. Alternatively, the lens can also be omitted, whereby the properties of the luminophore and the nature of its embedding or its geometry determine the radiation characteristic. Basically, the luminophore emits diffuse light. If, for example, the luminophore is sunk, the wall of the depression limits the opening angle and in this way brings about a radiation which is more or less directed, depending on the geometric conditions. Alternatively, the luminophore may be free-standing and elevated in relation to its surroundings, whereby a particularly large opening angle is achieved, since the luminophore can still radiate practically in the plane of the surface into which it is embedded.

In the prior art outdoor lights are known in which light-emitting diodes are used. These are diode types with superior plastic lens optics. The light-emitting diodes used are designed as light-emitting diodes for through-hole mounting. The diodes for through-hole mounting generally have two metallic leads that can be inserted through a support plate and soldered to the back of the support plate. There are various designs known, for example, mushroom lights, post-top lights, arc lights, whip lights or Seilhängeleuchten.

The Japanese patent application 2003-100111 A discloses a street lamp having a large emission area with a small number of light-emitting diodes.

US 2004/0095777 A1 discloses a lighting device having a plurality of high power light emitting diodes disposed on a heat sink and surrounded by a diffuser. The heat sink serves to deliver the heat generated by the LEDs to the expressed environment of the lamp.

The US2007 / 0195527 US 5,478,807 discloses an LED lighting source having a housing adapted for connection to an AC power source, a rectifier circuit for converting the AC power to a DC power, a power control circuit disposed in the housing and electrically connected to the AC power source, a series of electrical connections between a control node of the Power control circuit and the DC power source connected light emitting diodes, wherein the LEDs of the series are connected in series and have a number which is chosen so that they cause a voltage difference across the power control circuit, which is sufficient to operate active components of the power control circuit, if of the DC power source and the power control circuit are operated to limit a forward current through the row to a nominal forward current of a single light emitting diode.

Object of the present invention is compared to this prior art to provide a lighting fixture for outdoor lighting, which is a very compact light-emitting Has element so that a lamp equipped with it can be made very compact and yet has a high light output.

According to the invention, this object is achieved with a luminaire for outdoor lighting with at least one light-emitting diode array and a housing, wherein the light-emitting diode array has a plurality of light-emitting diodes which are surface-mounted on a single support, wherein the light-emitting diodes comprise a diode element and an element associated therewith with a luminophore, wherein the diode element and the element associated therewith are arranged such that the light generated by the diode element during operation excites the luminophore, wherein the light emitting diode array is disposed in the housing, wherein the housing is closed and has a substantially transparent portion, and with a arranged in the housing heat conducting element, wherein the heat conducting element has a fixing portion and at least one cooling section arranged in the housing, wherein the carrier of the light emitting diode array thermally conductively connected to the mounting portion of the heat conduction element is connected, and wherein the cooling section has at least one surface-enlarging element for releasing heat to the air in the interior of the housing solved.

Surface-mounted light-emitting diodes in so-called SMD packages are soldered directly onto the surface of a carrier. SMD LEDs have the great advantage that the chip can be arranged near the bottom inside the housing of the SMD LED, which allows a good heat transfer from the chip through the housing into the surface of the carrier plate. Due to the small external dimensions and the improved heat dissipation a much higher integration density of the SMD LEDs is possible. The carrier itself may be made of aluminum, or other highly conductive metals, such as copper; However, there are also known versions with a plastic board. A thermally even better version of the surface mount is the chip-on-board technology. In this case, the chips of the LEDs are not first applied in a housing, but directly on the surface of the carrier. The thermal resistance through the housing bottom is eliminated. The possible integration density is even higher due to the space savings and better heat dissipation.

A lighting fixture according to the invention with surface-mounted light-emitting diodes has the advantage that it can be made compact by the compact light-emitting diode array itself. Due to these small dimensions, it is possible to use a lighting fixture according to the invention to replace lighting fixtures in existing outdoor lighting.

Advantageously, a grid in the light emitting diode field is less than 5.6 mm. This ensures that a high luminance of the LED array is achieved. This in turn requires small dimensions.

Advantageously, the emission characteristic of the light emitting diodes is substantially influenced by the luminophore. As a result, a radiation of white light with a large opening angle is possible in a simple manner.

The carrier of the light emitting diode array is thermally conductively connected to a mounting portion of the heat conducting element. The heat-conducting element consists of several sections. The first section serves to absorb the heat from the carrier of the LED array and forward it to the other sections. At least one of the further sections is thermally conductive with other elements for heat dissipation or directly with a heat sink in combination. These Heat sink absorbs the heat generated by the light emitting diode array so that the light emitting diode array itself does not overheat.

Due to the enclosed housing, the elements of the lighting fixture arranged inside the housing can withstand external influences such as rain or dust. Electrical and electronic components are protected from moisture even when exposed. The transparent section lets the light escape from the housing. The disadvantage of such a closed housing, however, is that the heat generated can not be readily dissipated into the environment.

In one embodiment, the heat-conducting element has at least one cooling section arranged in the housing.

This cooling section of the heat-conducting element conducts the heat, which is introduced into the heat-conducting element in the fastening section, further in the direction of a heat sink, as a result of which the section has a cooling effect on the light-emitting diode array. This portion of the heat conducting element is disposed within the housing to dissipate the heat from the mounting portion, which is also located within the housing.

The cooling section can advantageously have at least one surface-enlarging element, in particular at least one cooling rib and / or at least one cooling bore, and release heat to the air in the interior of the housing, and / or at least one recess for improving the heat conduction in the longitudinal direction of the heat-conducting element, in particular at least one Heat transfer hole in the longitudinal direction of the heat conducting element included.

A cooling section according to this embodiment can transmit the heat emitted by the light emitting diode array (s) to the air located within the lighting fixture. This in turn is in communication with the inner surfaces of the housing, which advantageously has a low conductivity to the outside and, for example, advantageously consists of aluminum. As a result, the air in the interior of the lighting fixture can transmit the heat generated by the light-emitting diode fields via convection to the insides of the housing. Cooling fins or cooling holes on the heat-conducting element increase the contact area and thus the thermal transition between the heat-conducting element and the air. This transfers the heat more effectively to the air within the lighting fixture. The housing which surrounds the light emitting diode arrays and the heat conducting element, the inner surface, which absorbs the heat from the air again, is significantly larger, so that in one embodiment can be dispensed with measures to increase the thermally effective surface. Advantageously, a fan is arranged in the housing, the heat transfer by forcibly circulating the Air improves. The surface-enlarging element may be formed integrally with the heat-conducting element or be a separate element attached thereto.

The cooling section can also achieve a cooling effect by heat conduction to one or more heat sinks outside the lighting fixture. To support this, the cooling section can consist of thermally highly conductive material. In addition, the heat transfer can be improved by one or more internal recesses, which extend substantially in the transport direction of the heat to be dissipated by the heat conducting element, in particular bores or cylindrical recesses, in which the heat is transported faster by a medium flowing through. The medium may be a gas, for example air, or a liquid, for example water with an antifreeze, or alcohol or other liquid, e.g. a liquid organic compound, which advantageously still remains liquid even in the temperatures typically occurring on the heat-conducting element in winter and which does not yet boil at atmospheric pressure in the summer which typically occurs at the heat-conducting element. Advantageously, the bores can be connected at their ends for the overflow of medium from one bore to another bore, so as to provide a circuit in which the cooling medium can circulate and so by passive, or by forced with a pump or a fan Convection to dissipate heat.

An amount of water can also be used to increase the heat capacity of the heat conducting element with little weight gain, since water has a low specific gravity and a very high heat capacity. The usability of the heat capacity is described below.

The recess for improving the heat transport can also use the principle of a heat pipe (heat pipe). In this case, a liquid medium evaporates or evaporates at a point to be cooled within the recess, which is advantageous for the present invention in or near the attachment portion, and is reflected in a cooler place down. This is generally in the direction of the heat sink, which ultimately absorbs the heat, whereby the heat transfer can be significantly improved. The return transport of the medium to the point to be cooled takes place by capillary force along wick elements or on the surface of the wall of the recess, which is advantageously structured in the transport direction, and / or by gravity. The recess is advantageously sealed tight to hold the media therein. Alternatively, a prefabricated, sealed heat pipe can be introduced into a recess for improving the heat transport. This is advantageous at least at the point to be cooled with good thermal transfer to the wall of the recess.

In a further embodiment, the heat-conducting element has two cooling sections, which are arranged such that the fastening section extends between the cooling sections.

By arranging the cooling sections around the attachment section, the heat is better dissipated since it can propagate in two directions toward a heat sink. In addition, this arrangement makes it possible to fix the light-emitting diode array centered on the heat-conducting element, whereby it can also be arranged in the center of a lamp. This in turn means more freedom in the design of elements for influencing the illumination around the light-emitting diode array.

The heat-conducting element is advantageously designed in several pieces, wherein preferably the attachment portion and a cooling portion form separate parts.

The use of a multi-part heat conducting element affords the possibility of separating the light emitting diode array together with the first part on which the fixing section is arranged from a further part of the heat conducting element, on which the cooling section is arranged, in the case of a defective or used light emitting diode field. The advantage is that the junction between the light emitting diode array and the portion with the mounting portion need not be disconnected while installed in the lamp. This may be due to circumstances when changing, e.g. Working at great heights on a slightly unstable aerial work platform, possibly even in cold weather, and a difficult operation due to the small size of the light emitting diode panel fasteners, such as small screws or clamps. This operation may be performed after removal of the first part with the mounting portion and the light-emitting diode array under suitable conditions, e.g. in the factory. On the other hand, the part of the heat-conducting element with the light-emitting diode array can be fastened to a further part of the heat-conducting element or other elements of a lamp by fastening means which are easy to detach even under difficult conditions. A lamp base or a lamp cover, which dissipates heat by solid conduction from the housing, for example into a mast or to the ambient air, can also be a part with a cooling section of the heat-conducting element due to its cooling function. The attachment portion portion may additionally include cooling portions located on the portion.

In a further embodiment, the cross section of the fastening section is a polygon, preferably a quadrangle or a triangle and particularly preferably an equilateral triangle, wherein at least one light-emitting diode array is thermally conductively connected to one, several or each of the side faces of the fastening section.

Such a design of the mounting portion of the heat conducting element offers several advantages. The execution of the cross section over the portion to which at least one light emitting diode array is attached, as a polygon allows that flat surfaces are present, where the Carrier of the LED array can rest flat. This ensures a good heat transfer between the carrier in the first part of the heat conducting element. Another advantage is that the lighting fixture can be adapted to the lighting situation by the design as a regular or irregular polygon. If, for example, the opening angle of the light-emitting diode array is 120 °, all-round lighting with a mushroom lamp on a mast with an equilateral triangle can be achieved. For example, if one area is to be left open and another area is to be more strongly illuminated, an isosceles or irregular triangle can be used as a cross section for the first part of the heat conduction element, with one or more light emitting diode arrays being applied to two of the three sides. For example, in the case of an arc lamp, it may be advantageous to illuminate the edge regions of the illumination which are farther from the lamp, in order to achieve a generally wider illumination with a lamp. For targeted stronger illumination of several angular directions and quadrangles or pentagons can be used and by setting the angle in the respective polygons the emission characteristics are determined.

In one embodiment, the cross-section of the attachment portion is a pentagon, with only three of the side surfaces of the attachment portion being connected to light-emitting diode arrays.

Particularly advantageous is the execution as a pentagon, in particular as an irregular pentagon, in which three surfaces are perpendicular to each other and the two other surfaces are at an acute angle to each other and at an obtuse angle to the first three surfaces. The obtuse angles are advantageously the same size. On the middle of the three mutually perpendicular surfaces and the two surfaces at an acute angle to each other is advantageously arranged in each case a light-emitting diode array. With such an arrangement, it is possible to make a targeted illumination of a street with a lamp in which such an element is arranged vertically, for example with a mushroom lamp. The pentagon is arranged in the lamp so that the two light emitting diode arrays, which are arranged on the pointed surfaces, illuminate the street, and the third of the light emitting diode fields illuminated the walkway and possibly existing buildings. It is also possible to use cross-sections with polygons of even higher order than five in order to make the illumination even more targeted. The polygonal design of the first part of the heat-conducting element therefore makes it possible in a simple manner to adapt the emission characteristic of a lighting fixture to the place of use.

In order to be able to apply light-emitting diode arrays to the surfaces of the polygons, it is necessary for the polygonal cross-section of the first part of the heat-conducting element to be constant at least over the length or the width of a light-emitting diode array. Alternatively, the surfaces on which the light-emitting diode arrays are arranged may be inclined to the longitudinal axis of the heat-conducting element, that is, for example, the surfaces of the mounting portion may be a truncated tetrahedron or form a truncated pyramid or corresponding bodies with pentagonal or irregular polygonal cross-section. In this way, the light of the LED array can be directed downwards, thereby the light can be used more effectively to illuminate the street, as it is directed directly there. The thermally conductive connection between the first part of the heat conducting element and the light emitting diode array is preferably realized by pressing the carrier to the first guide element and advantageously improved by the introduction of thermal paste in the connection point.

In a further advantageous embodiment, the first part of the heat-conducting element of the lighting fixture for outdoor lighting has a continuous hole in the longitudinal direction.

Such a through hole offers the possibility of attaching the first part of the heat-conducting element by plugging on this hole to a counterpart. If the hole is located substantially in the center of the profile, heat flow from the LED panels to the heat sink (s) is only marginally impeded, provided that they are located at one or both ends in the longitudinal direction of the first part of the heat conducting element.

In a further embodiment of the lighting fixture for outdoor lighting, it has a lamp base, wherein, starting from the lamp base, a rod-shaped holding element for receiving the heat-conducting element extends.

The heat-conducting element can be plugged onto the rod-shaped retaining element. Such a connection has the advantage that the heat-conducting element with the light-emitting diode array can be easily separated from the lamp base, in particular if it is a mushroom lamp or a post-top luminaire. In this case, the lid can be removed, the optional existing attachment of the heat conduction on the rod or the lamp base or on a further element of the lamp can be solved and the first portion of the heat conducting element with the light emitting diode arrays are removed from the lamp. Advantageously, the lamp base is designed so that the axial end surface of the first part of the heat-conducting element abuts against a counter surface on the lamp base and is pressed against this. Alternatively or additionally, the cover or a further part of the heat-conducting element can be pressed against the opposite end of the first part of the heat-conducting element on the axial surface. Alternatively or in addition to the axial surfaces and the peripheral surfaces or the inner surface of the bore can be used as contact surfaces for a good heat transfer. The corresponding thermally connected counter-elements are advantageously formed in a corresponding area as a geometrically matching counterpart to the corresponding contact surface. Advantageously, thermal compound is introduced into the joints. Alternatively, the heat-conducting element can also be attached to the ends of a Clamping pin are pressed, which is arranged in a bore across the lamp base and overhangs.

As an alternative to the fact that the first part of the heat-conducting element has a continuous hole in the longitudinal direction, it may also have one or more holes in the transverse direction. They can serve for fastening the first part of the heat-conducting element to a lamp base or to other parts of the lamp. The arrangement in the transverse direction has the advantage that with bulbs that are to be opened at the periphery, such as arc lamps, which are attached to a curved mast, a simpler replacement of the first part of the heat conducting is possible.

Due to the thermal connection with the heat-conducting element and the associated cooling effect on the light-emitting diode array, the lamp base can be part of the heat-conducting element, which has a cooling section.

In a further embodiment, the rod-shaped holding element has a threaded portion at its end remote from the lamp base.

On the threaded portion, a nut for fastening and pressing the heat-conducting element are screwed to the lamp base.

In a further embodiment, the lamp base engages through the housing and has on the outside a receptacle for a mast.

This creates a stable connection between the mast and the heat conducting element. In addition, a heat dissipation possibility out of the housing is created by the lamp base in this way establishes a thermal connection between the heat conducting element and thus the light emitting diode array and the mast, if it has a suitable thermal conductivity.

In a further embodiment, the lamp base and / or the heat-conducting element consists essentially of metal, preferably of aluminum.

By means of such a material, a good thermal conductivity of the first part of the heat-conducting element or the lamp base is ensured. Aluminum can be used for a particularly good cost / benefit ratio since the thermal conductivity is comparatively high compared to the price per volume. In addition, the dimensions of the first part of the heat conducting element or the lamp base can be smaller compared to other metals, since the thermal conductivity is higher.

Another embodiment of the lighting fixture for external lighting is designed so that the heat-conducting element is thermally conductively connected to an element outside the housing, preferably with a lampshade or a mast, which in turn is thermally connected to a heat sink outside the housing or even represents such is.

The elements or components mentioned serve to couple the heat flow from the light-emitting diode array to a heat sink. Heat sinks may be, for example, the ambient air, a large part of the building or the ground. In this way, the LED array is thermally connected to one or more heat sinks. The connection of said elements to the ambient air can be improved by increasing the surface area. For this purpose, cooling fins may be arranged on the respective elements, which advantageously extend vertically, in order to allow a better passing of the air through thermal convection. For thermal connection with one of the heat sinks, in particular ground or building part, the mast or other fastening means which connect the lamp with the heat sink, be performed thermally well conductive. For this they can, for example, consist essentially of aluminum.

A good thermal connection is achieved, for example, by bringing a heat sink, which consists of solid material, as large as possible in direct contact with the heat-conducting element. For example, a surface of the heat-conducting element can be pressed against a surface of the heat sink. Advantageously, to improve the heat transfer, a thermal paste can be introduced into the connection point. If the heat sink is gaseous, for example the ambient air, then a thermally well-conductive coupling can be realized, for example, by cooling fins, which communicate with the ambient air over an enlarged area. The large outer surfaces of a mast or a lid in itself can already represent a good coupling. The mast can thus emit heat both into the ground and to the ambient air.

In an embodiment in which portions of the heat conducting member receive heat during the operating cycle of the light emitting diode array to deliver it to a heat sink outside the housing during the off state of the light emitting diode array, a thermal transition to a heat sink enables only this mode of operation by absorbing the heat received from the heat sink Heat capacity during the period in which no operation takes place, can flow to the heat sink. If the thermal capacity of the heat conducting element is small compared to the amount of heat dissipated per cycle of operation, the thermal transition to the heat sink ensures that the heat generated by the diode array can be dissipated to the heat sink without significant buffering so that the light emitting diode array does not overheat , An operating cycle is typically a duty cycle during one night.

In a further embodiment of a lighting fixture for external lighting, the heat capacity of the heat-conducting element is chosen such that it can absorb the heat emitted by the light-emitting diode field of an operating cycle minus the effluent during the operating cycle heat, the temperature of the LED array does not exceed the permissible temperature during operation.

One skilled in the art will appreciate that the heat capacity of an element can be calculated from the specific heat capacity, which is material dependent, multiplied by the volume of the element. The heat that absorbs such a heat capacity is determined by the heat capacity multiplied by the temperature difference that undergoes the heat capacity. The heat that emits the light-emitting diode array during an operating cycle can be calculated by a person skilled in the art by multiplying the power loss of the light-emitting diode array by the operating time. In order to realize a suitable heat capacity of the heat-conducting element, the heat-conducting element can be realized from a material having a suitable specific heat capacity in conjunction with a suitably large volume. During the design, it must be taken into account that the temperature increase that the heat-conducting element experiences as a result of the heat storage does not go so far that the permissible temperature of the LED field is exceeded. This design model does not take into account that heat can also flow away during this time.

In a further embodiment, the lighting fixture illuminates a reflector element.

A reflector element can influence the emission characteristic of a luminaire. It is advantageously positioned and shaped in such a way that the desired emission characteristic is produced, for example it reflects light emitted upwards downwards in the direction of a road. For this purpose, it can be designed, for example, annular and be arranged above one or more light-emitting diode arrays.

Advantageously, in another embodiment, the heat dissipation of the light emitting diode array is thermally dimensioned so conductive that the heat flow from the LED array generates a maximum of a temperature difference between one or more heat sinks and the LED array, through which the LED array does not exceed a maximum allowable temperature.

One skilled in the art will appreciate that the thermal resistance of an element is calculated from the thermal conductivity of the material making up the element multiplied by the cross section of the element divided by the length of the element. If these quantities are not constant, it can be integrated to calculate the thermal resistance. Alternatively, for a high accuracy calculation, a finite element simulation of the thermal relationships be carried out to determine the thermal resistance of the element. To increase the heat dissipation, the cross section of the heat conducting element can be increased transversely to the direction of the heat flow, the length can be reduced in the direction of the heat flow, or a thermally more conductive material can be used. The heat sink represents the environment. This has the property that its temperature does not increase significantly, although heat from the LED array flows into it via the heat conducting element. By the temperature of the heat sink and a permissible temperature of the LED array, a temperature difference can be defined, which can flow the heat from the LED array through the heat-conducting. For the design of the thermal resistance, the temperature of the heat sink is defined as the maximum temperature that occurs during permissible operation, for example the temperature which the heat sink has on a warm summer night. The permissible temperature of the LED field is determined by the thermal capacity of the diodes. The permissible temperature is determined by the manufacturer of the light-emitting diodes or the light-emitting diode array used and can be, for example, 70 ° C.

If several heat sinks are present, there is a parallel connection of parts of the heat conducting element to the heat sinks. If the heat sinks have different temperatures, e.g. a mast and the ambient air, the individual thermal resistances of the parts of the heat-conducting element from the light-emitting diode array to the heat sink are advantageously designed so that the heat dissipation via the respective thermal resistances produce maximum temperature differences between the light-emitting diode array and the respective heat sinks, which lead to the permissible temperature at the LED field is not exceeded. For this purpose, not necessarily only a thermal resistance has to be designed accordingly, but the fulfillment of the criterion that the permissible temperature at the light-emitting diode array is not exceeded can be achieved by designing several or all of the thermal resistances.

The types of design to temporarily store the heat during the operating cycle in the heat conducting element or to dissipate the heat via the heat conducting in a heat sink, flowing into each other, as always both effects occur simultaneously. It therefore flows when starting the operation of heat in the heat capacity, in addition, heat is dissipated from the heat-conducting in a heat sink. An integrated design thus takes into account both effects. The heat capacity of the heat-conducting element can therefore be chosen smaller at the same temperature conditions corresponding to the amount of heat that is emitted from the heat-conducting element by heat dissipation to a heat sink. The thermal resistances and the heat capacity can be adjusted to one another in such a way that the permissible temperature of the light-emitting diode array is not exceeded.

In a further embodiment, the lighting fixture for external lighting comprises a plurality of light-emitting diode arrays, preferably three light-emitting diode arrays.

With light-emitting diode arrays, which typically have an opening angle of 120 °, all-round illumination can be achieved with just three light-emitting diode arrays. The light-emitting diode arrays are advantageously arranged in this case at an angle of 60 ° to each other.

In a further embodiment, the housing for a lighting fixture for outdoor lighting dustproof and waterproof, and preferably after at least IP 54 dust and waterproof.

Since lamps for outdoor lighting are exposed to the harsh environmental conditions, of which especially rain and dust are harmful to the lighting fixture, it is advantageous to protect the lighting fixture inside the lamp housing in front of it. The degree of protection IP 54 means protection against splashes of water on all sides and protection against dust deposits. Such protection can be achieved by a design of the housing with seals or sealant at the points where touch parts of the housing. Alternatively, the tightness can be achieved without seals by a high manufacturing quality and good fits.

In a further embodiment, the light emitting diode array and the first part of the heat conducting element are advantageously made so compact that existing other types of light sources, such as the filament of sodium vapor lamps or mercury vapor lamps, can be replaced by them. The dimensions of the first part of the heat-conducting element with the light-emitting diode field do not exceed the corresponding dimensions of the luminous body to be replaced.

In a further embodiment, the lamp base of a lighting fixture according to the invention is designed so that an existing base or lamp base for a luminous element can be exchanged for a lamp base according to the invention. For this purpose, in particular, the fastening points of the lamp base are designed so that for fastening the fastening means can be used, which are also used to attach the socket to be replaced. It can also be used only parts of the fastening means, for example, only holes through the lamp housing or other parts of the lamp.

• Figur 1 einen Querschnitt einer Pilzleuchte nach dem Stand der Technik,
• Figur 2 einen Querschnitt einer Pilzleuchte gemäß einer Ausführungsform der Erfindung,

die Figuren 3A bis 3C Querschnitte durch das in der Figur 2 gezeigte Wärmeleitelement mit einem Befestigungsabschnitt mit fünfeckigem Querschnitt, und
die Figuren 4A bis 4C zeigen Querschnitte durch das in der Figur 2 gezeigte Wärmeleitelement mit einem Befestigungsabschnitt mit dreieckigem Querschnitt.Further advantages, features and possible applications of the invention will become apparent from the following description of preferred embodiments and from the accompanying figures. Show it:

• FIG. 1 a cross section of a mushroom lamp according to the prior art,
• FIG. 2 a cross section of a mushroom lamp according to an embodiment of the invention,

the FIGS. 3A to 3C Cross sections through in the FIG. 2 shown Wärmeleitelement with a mounting portion with pentagonal cross-section, and
the FIGS. 4A to 4C show cross sections through the in the FIG. 2 shown Wärmeleitelement with a mounting portion with triangular cross-section.

In the figures, the reference numerals are chosen so that the first digit corresponds to the number of the figure. The following numbers indicate the features and elements in the figures, wherein corresponding sequence numbers with different first numbers indicate the same or similar, similar features and elements in another figure.

In FIG. 1 FIG. 12 shows a cross section of a prior art mushroom lamp 100. The mushroom lamp 100 consists of a lamp base 101, a luminous means carrier 102 which carries a lighting means 103, for example a light bulb, a neon tube or a mercury or sodium vapor lamp, a cover 104, a screen 105 which surrounds the illuminant carrier 102 and a transformer 106, which is arranged in the illuminant carrier 102. The cover 104 is connected to a connecting piece 107 with the illuminant carrier. The screen 105 is transparent so that the illuminant can illuminate the surroundings of the mushroom lamp all around. The illuminant carrier 102 is inserted into the lamp base 101 and secured with a stud screw 108. The lamp base 101 also carries the screen 105.

FIG. 2 on the other hand shows a cross section through a mushroom lamp 200 according to the invention, which is modified with a heat conducting element 202 and a light-emitting diode array 203 according to the invention. The lamp base 201 of the embodiment of the present invention is identical to the prior art lamp base 201, as well as the lampshade 205 and the lid 204.

On the lamp base 201, the heat conducting element 202 is arranged according to the invention. The heat-conducting element 202 consists of a lower section 221, which is designed as a heat sink, a middle section 220, which carries three light-emitting diode arrays 203 as the fastening section, and an upper section 222, which is likewise designed as a heat sink. By the heat conducting element 202 extends a bore 312 in the longitudinal direction, through which a tube 211 is inserted. The tube 211 is fixed in the lamp base 201 with a stud 208. The Wärmeleitelement 202 is pulled by a thread at the end of the tube 211, which faces the cover 204, and a nut 210 against a dowel pin 209 which is inserted through a bore which extends transversely through a directed to the heat conduction member, and projects from it , The heat-conducting element is safely connected to the tube 211 in this way. The tube 211 protrudes into a receptacle 207 on the inside of the lid 204 and thus ensures the alignment of the heat-conducting element 202 in the mushroom lamp 200. By this construction, the heat conduction member 202 can be easily removed from the mushroom lamp by removing the lid, unscrewed the nut 210 and the heat conducting element is withdrawn from the tube 211 upwards. The installation can be done in the same simple way in reverse order.

The light-emitting diode array 203 is screwed onto the middle section 220 of the heat-conducting element 202. At the lower portion 221 of the Wärmeleitelements 202, a transformer 206 is arranged, which supplies the light-emitting diode arrays with electrical energy from the customary low-voltage network.

FIG. 3A shows a substantially square cross section through the upper portion 322 of the Wärmeleitelements 202. In the middle of the cross section, the through hole 312 is arranged. On all four sides of the upper portion 322 of the Wärmeleitelements cooling fins 313 are arranged.

FIG. 3B shows a cross section of the Wärmeleitelements 202 in its central portion 220, 320. In this section 320, the Wärmeleitelement 202 has a pentagonal cross-section. It is an irregular pentagon, in which three of the adjacent sides 314, 315 and 316 are connected by right angles and the two other sides 317 and 318 are at an acute angle to each other and each with an obtuse angle> 90 ° to the Pages 315 and 316 are connected. Pages 315 and 316 have equal lengths. The sides 314, 317 and 318 each carry a light emitting diode array 303. Inside the cross section, the through hole 312 is arranged approximately at the centroid.

The formation of the cross section as an irregular pentagon with the said occupancy of the sides with light-emitting diode arrays has the advantage that the emission characteristic of the lamp is favorably influenced for outdoor lighting. The two light-emitting diode arrays on pages 317 and 318 serve to illuminate a street, the angles being chosen so that the main direction of emission from the individual light-emitting diodes is oblique towards the street and further illuminates it in comparison to all-round omnidirectional illumination. The LED field on page 314 illuminates the walkway and buildings behind. When replacing the Wärmeleitelements therefore the installation of a replacement part must be done with the same angular orientation. To facilitate this, a device may be provided which allows the correct installation only in the correct angular orientation.

In the FIG. 3C is a cross section of the heat conducting element in its lower portion 321 shown. In the middle of the cross section, the through hole 312 is arranged. Three of the sides of the substantially rectangular cross section are formed as cooling fins 319. On the fourth side, a transformer 306 is fixed to the lower portion 321 of the heat conducting member 302.

FIG. 4A shows a substantially square cross section through the upper portion 422 of the Wärmeleitelements 202. In the middle of the cross section, the through hole 412 is arranged. On all four sides of the upper portion 422 of the Wärmeleitelements cooling fins 413 are arranged.

FIG. 4B shows a cross section of the Wärmeleitelements 202 in its central portion 220, 420. In this section 420, the Wärmeleitelement 202 has a triangular cross-section. This is an equilateral triangle, with the three sides 414, 417 and 418 connected by equal angles of 60 ° each. The sides have the same lengths and each carry a light emitting diode array 403. Inside the cross section, the through hole 412 is arranged approximately in the centroid.

The formation of the cross section as an equilateral triangle with the above-mentioned occupancy of the sides with light-emitting diode arrays has the advantage that the emission characteristics of the luminaire despite the use of only three light-emitting diode fields complete coverage when the LED array has an opening angle of at least 120 °. This allows a uniform ring-around lighting can be realized.

In the FIG. 4C a cross section of the heat conducting element is shown in its lower portion 421. In the middle of the cross section, the through hole 412 is arranged. Three of the sides of the substantially rectangular cross section are formed as cooling fins 419. On the fourth side, a transformer 406 is fixed to the lower portion 421 of the heat conduction member 202.

LIST OF REFERENCE NUMBERS

100

Cross section of a mushroom lamp according to the prior art

101

Lampenfuß

102

Lamp support

103

Lamp

104

cover

105

umbrella

106

transformer

107

joint

108

stud

200

Cross section of a mushroom lamp according to the invention

201

Lampenfuß

202

thermally conductive element

203

LED array

204

cover

205

umbrella

206

transformers

207

admission

208

stud

209

dowel pin

210

mother

211

pipe

220

Middle section of the heat conducting element

221

Lower section of the heat conducting element

222

Upper section of the heat conducting element

303

LED array

306

transformer

312

Through Hole

313

cooling fins

314

First page of the pentagon

315

Second side of the pentagon

316

Third side of the pentagon

317

Fourth side of the pentagon

318

Fifth side of the pentagon

319

cooling fins

320

Cross section of the central portion of the heat conducting element

321

Cross section of the lower portion of the heat conducting element

322

Cross section of the upper portion of the heat conducting element

403

LED array

406

transformer

412

Through Hole

413

cooling fins

414

First side of the triangle

417

Second side of the triangle

418

Third side of the triangle

419

cooling fins

420

Cross section of the central portion of the heat conducting element

421

Cross section of the lower portion of the heat conducting element

422

Cross section of the upper portion of the heat conducting element

Claims (13)

1. A lighting body for external illumination comprising at least one light emitting diode array (203) and a housing (201, 204, 205),
   wherein the light emitting diode array (203) has a plurality of light emitting diodes surface mounted on a single carrier,
   wherein the light emitting diodes have a diode element and an element associated therewith and having a luminophore,
   wherein the diode element and the element associated therewith are so arranged that the light produced by the diode element in operation excites the luminophore,
   wherein the light emitting diode array (203) is arranged in the housing (201, 204, 205),
   wherein the housing (201, 204, 205) is closed and has a substantially transparent portion (205),
   and comprising a heat-conducting element (202) arranged in the housing (201, 204, 205),
   wherein the heat-conducting element (202) has a fixing portion and at least one cooling portion (221, 222) arranged in the housing (201, 204, 205), wherein the carrier of the light emitting diode array (203) is thermally conductingly connected to the fixing portion (220) of the heat conducting element (202), characterised in that the cooling portion (221, 222) has at least one surface-enlarging element for the delivery of heat to the air in the interior of the housing (201, 204, 205), and wherein the heat-conducting element (220) has at least one through hole (312) in the longitudinal direction.
2. A lighting body for external illumination according to claim 1 characterised in that the cooling portion (221, 222) has at least one cooling rib (313, 319) and/or at least one cooling bore and/or includes at least one opening for improving heat conduction in the longitudinal direction of the heat-conducting element, in particular at least one heat transport bore in the longitudinal direction of the heat-conducting element.
3. A lighting body for external illumination according to one of the preceding claims characterised in that the heat-conducting element has two cooling portions (221, 222) so arranged that the fixing portion (220) extends between the cooling portions (221, 222).
4. A lighting body for external illumination according to one of the preceding claims characterised in that the heat-conducting element (202) is of a multi-part structure, wherein preferably the fixing portion (220) and a cooling portion (221, 222) form mutually separated parts.
5. A lighting body for external illumination according to one of the preceding claims characterised in that the cross-section of the fixing portion (220, 320) is a polygon, preferably a quadrangle or a triangle and particularly preferably an equilateral triangle, wherein at least one light emitting diode array (203, 303) is respectively thermally conductingly connected to one, a plurality or each of the side surfaces (314, 315, 316, 317, 318) of the fixing portion (220).
6. A lighting body for external illumination according to one of the preceding claims characterised in that the cross-section of the fixing portion (220, 320) is a pentagon, wherein only three of the side surfaces (314, 315, 316, 317, 318) of the fixing portion (220, 320) are connected to light emitting diode arrays (203, 303).
7. A lighting body for external illumination according to one of the preceding claims characterised in that it has a lamp base (201), wherein a rod-shaped holding element (211) for receiving the heat-conducting element (202) extends from the lamp base (201).
8. A lighting body for external illumination according to one of the preceding claims characterised in that at its end remote from the lamp base (201) the rod-shaped holding element (211) has a threaded portion.
9. A lighting body for external illumination according to one of the preceding claims characterised in that the lamp base (201) engages through the housing (201, 204, 205) and on the outside has a receiving means for a mast.
10. A lighting body for external illumination according to one of the preceding claims characterised in that the lamp base (201) and/or the heat-conducting element (202) substantially comprise metal, preferably aluminium.
11. A lighting body for external illumination according to one of the preceding claims characterised in that the heat-conducting element (202) is thermally conductingly connected to an element outside the housing (201, 204, 205), preferably to a lampshade (205) or a mast, which in turn is thermally connected to a heat sink outside the housing (201, 204, 205) or itself represents such a sink.
12. A lighting body for external illumination according to one of the preceding claims characterised in that the thermal capacity of the heat-conducting element (202) is so selected that it can absorb the heat delivered by the light emitting diode array (203) in an operating cycle less the heat which is dissipated during the operating cycle, wherein the temperature of the light emitting diode array does not in operation exceed the permissible temperature.
13. A lighting body for external illumination according to one of the preceding claims characterised in that the lighting body illuminates a reflector element.

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