FR2913483A1 - LED illumination device for illuminating e.g. public road, has static type heat dissipation unit dissipating heat provided at level of face of plate, where unit is formed by cooling fins connected on upper surface of plate - Google Patents

Abstract

The device (16) has LEDs (18) connected on a plane support board (20) that is in form of a printed circuit plate. A support block (22) has a plate (48) whose one face forms a planar bottom (40) of a parallelepiped shaped housing (36) in which the board is placed. The housing is closed by a luminous ray processing unit (24) i.e. optimal element, processing luminous rays emitted by the LEDs. A static type heat dissipation unit (44) dissipates heat provided at a level of another face of the plate (48), where the unit (44) is formed by cooling fins connected on an upper surface of the plate (48).

Description

LEB LIGHTING DEVICE

  The present invention relates to a lighting device LEb. A lighting device intended for public lighting, or more generally for outdoor lighting, generally comprises a lamp mounted in a lantern fixed to the upper end of a mast or on a support situated at a sufficient height. This type of lighting must meet standards concerning the quality of the lighting, particularly in terms of luminous flux, luminance, area of the illuminated area, uniformity of luminance on said area and dazzling of the source .

  For example, a lighting device intended for street lighting must illuminate a substantially rectangular surface on the ground of approximately 24 meters by 6 meters, with illumination greater than 10 lux, for example, and a relatively high luminance. homogeneous on said zone. Current lamp-type lighting devices consume a lot of energy for average lighting quality and high maintenance costs. Lighting devices LEb are now considered an advantageous alternative in terms of lower consumption of electrical energy and increase the life of said device. Furthermore, a lighting device LEb is expected to obtain a precision of illumination with a controlled amount of light. However, the use of LEb for lighting may be problematic for the following reasons. A LEb has a large lighting angle, which causes widespread diffusion and loss of light in an application intended to illuminate an area far from said LEb. Also, the LEb is generally associated with means of concentration to gather the light rays in a beam of maximum light intensity oriented towards the target to be illuminated. According to another problem, an LEb has a relatively low luminous power so that it is necessary to associate several LEb in order to obtain a luminous power substantially equivalent to that of a lighting device using a lamp. When several LEb are associated they are grouped in the form of bars or light spots generally comprising three LEb. Given these constraints, LEb lighting devices are generally used for directional lighting to illuminate a small area in the manner of a projector illuminating a performance stage.

  There are LEb lighting devices for public lighting with LEb or LEb strips reported on curved supports in order to orient the LEb light beams towards an enlarged area. However, in this case, the support is relatively large and complex to illuminate an enlarged area as defined by the standard.

  However, a lighting device LEb must be compact to make it compatible with existing devices. Another problem inherent in the use of LEb in a lighting device concerns the dissipation of the heat produced by said LEb. Indeed, a LEb can not radiate heat and is not as resistant to high temperatures as an incandescent lamp filament for example. However, a public lighting device operates for several hours in a row making it difficult to use LEb insofar as the latter would cause a very high temperature rise likely to damage the LEC) but also the other electronic components necessary for operation LEC). Given all these constraints, the use of LECs for public lighting remains marginal.

  Also, the present invention aims to overcome the drawbacks of the prior art by providing a lighting device LEC) more particularly for outdoor lighting, simple design for achieving a life compatible with the market. For this purpose, the subject of the invention is an LEC lighting device, more particularly adapted for outdoor lighting, comprising a plurality of LECs attached to at least one support plate, characterized in that said lighting device has LEC) comprises a support block comprising a plate, one of whose faces forms the substantially plane bottom of a housing in which is placed said at least one substantially flat support plate so as to cooperate closely with the bottom of the housing, said housing being closed by light treatment means emitted by the LEC) and heat dissipation means provided at the other side of the support block plate. Other features and advantages will become apparent from the following description of the invention, a description given by way of example only, with reference to the accompanying drawings, in which: FIG. 1 is a representation of a lantern, FIG. 2 is a representation of an LEC lighting device according to the invention adapted to an existing lighting lantern; FIG. 3 is a representation of an exploded view of a lighting device in FIG. LEC) according to a variant of the invention, - Figure 4 is a representation of a power / life curve of a LEC) - Figure 5 is a schematic side sectional view of the lighting device LEb FIG. 6 is a representation of the means for concentrating the optical element of the LEb lighting device according to a variant of the invention; FIG. 7 is a representation of the orientation means of FIG. the optical element of the lighting device LEb according to a variant of the invention, - Figure 8 is a sectional representation of the concentration and orientation means illustrated in Figure 6 and 7, - Figure 9 is a side view of a Another variant of the lighting device according to the invention, - Figure 10 is a perspective view illustrating the different parts of the lighting device of Figure 9, - Figure 11 is a section illustrating in detail the treatment of light rays from the LEb of the device illustrated in FIGS. 9 and 10, FIG. 12 is a schematic representation illustrating the illumination on the ground obtained from the device of FIG. 9, FIG. 13 is a schematic representation of the implantation of LEb's. according to a preferred embodiment, - Figure 14 is a sectional view schematically illustrating the lighting device according to the invention, and - Figure 15 is a section illustrating the orientation of the light rays. issued by a LEb.

  In Figure 1, there is shown by way of illustration a lighting lantern 10 may be reported on a candelabrum against the facade of a building or other lighting medium. This lantern 10 comprises a frame 12 on which is fixed a shell 14, at least a portion, generally the lower part, is open or substantially transparent so as to let the light provided by a lighting device or lamp located at the The description will now be made for a LEC lighting device 16 according to a variant of the invention, capable of being placed in a lighting lantern 10 more particularly intended for external lighting. , including a public place such as a road or a street. This application, represented in FIG. 2, is in no way limiting the possibilities of using an LEC lighting device according to the invention.

  As illustrated in FIG. 3, a LEC lighting device 16 comprises several LECs 18 reported on at least one support plate 20 placed between a support block 22 and means 24 for processing the light beams emitted by the LECs). LEC) 18 being provided to provide a light output at least equivalent to that provided by existing lighting devices.

  The LECs 18 of the lighting device 16 are LECs of power between 1 and 5 W to give an order of ideas. These values are in no way limiting. Advantageously, the LECs 18 of the lighting device 16 are used at half of their maximum power of use. Thus, as shown in Figure 4 representing a power / life curve of a LEC), the LECs 18 are likely to offer a longer life, such as a life of about 50,000 hours corresponding for example to the specifications demanding a public lighting project. Preferably, the plurality of LECs 18 of the lighting device 16 are connected in series so as to simplify the regulation of their power supply, said device 16 being powered by a mains voltage in most lighting applications of a lighting device. object or place. However, parallel editing could be considered.

  The support plate 20 is in the form of a plate of a printed circuit on one of the faces of which are reported the LEb. According to a preferred embodiment, illustrated in FIG. 14, the LEb as well as the set of components (represented in the form of at least one module 26 in FIG. 14) notably ensuring the power supply and LEb management function. are attached to one of the faces of a flat support plate. According to another variant, the support plate 20 may comprise only the LEb on one of its faces, the components ensuring in particular the power supply and LEb management function being grouped together in the form of at least one implanted module 26 in another area of the device, for example at the rear of the support block. According to a preferred embodiment, the power supply and management of LEb can be carried out according to the assembly and with the components detailed in the French patent application No. 06 52033. Nevertheless, other solutions are possible.

  The LEb 18 can be implanted inside the device in the form of an LEb matrix (L1, L2, ..., Li, ..., Ln). The present invention is not limited to this arrangement of LEb, said LEb being able to be arranged according to other arrangements. Thus, the LEb could not be aligned but arranged according to curves.

  In Figure 13, there is shown an implementation of LEb to improve lighting, especially when it is suitable for a road. The LEb are arranged along substantially rectilinear lines 28, parallel to a first axis 30 corresponding to the direction of the largest dimension of the zone illuminated on the ground, and according to columns 32 substantially symmetrical along a median axis 34 (substantially perpendicular to the first axis 30), some columns 32 having a radius of curvature tending to spread the LEb of the central axis 34 as they move away from the first axis 30. Advantageously, the radius of curvature of the columns 32 decreases in function of the spacing between the column and the median axis 34. For example, the LEb are arranged in seven rows and eight columns. According to a preferred embodiment of the invention, the LEb are spaced apart by a step of the order of 20 millimeters between lines and between columns. This pitch of 20 mm between LEb advantageously decreases the size thus favoring the adaptation of the lighting device 16 to an existing lantern 10. However, this is a minimal step in order to ensure a compromise between the gain in size and an excessive proximity of LEb 18 which would disadvantageously favor their rise in temperature. In order to be disposed in a shell 14 of an existing lantern 10 and as illustrated in FIG. 5, the device 16 according to the invention comprises a support block 22 having fastening means on said shell 14 or directly on a frame 12 to which is attached the lantern 10 lighting. These fixing means of the support block 22 are not detailed here because they can be in many forms and are known to those skilled in the art. According to another variant, the lighting device forms a lantern as illustrated in Figures 9, 10 and 14. In this case, the lighting device of the invention comes instead of existing lanterns.

  According to the invention, whatever the variant, the support block 22 comprises a housing 36 provided for receiving at least one support plate 20 of LEb, said housing being closed by the means 24 for processing the light rays emitted by the LEb. This housing 36 is substantially parallelepipedal and of sufficient depth to accommodate the superposition of at least one support plate 20 of LEb and means 24 for processing the light rays emitted by the LEb. This housing 36 comprises side walls 38 and a bottom 40.

  The bottom 40 is substantially plane to cooperate closely with said at least one support plate 20 also flat to ensure efficient heat transfer between the support plate 20 and the support block 22. The support plate 24 of LEb is fixed on the bottom 40 by fastening means such as fixing screws. Advantageously, conduction means 42 can be provided to efficiently transfer the heat dissipated by the LEb to the support block 22. These heat conduction means 42, interposed between a support plate 20 and the support block 22, can be produced by a thermally conductive but electrically insulating film. The fixing means of the support plate 20, substantially compressing the heat conduction means 42, optimal transfer of the heat generated by the LEb to the support block 22 is ensured. In order to evacuate the heat generated by the LEb 18 and transmitted to the support block 20, the lighting device 16 according to the invention has heat dissipation means 44 of the static type and means for generating a forced air flow 46. Said heat dissipation means 44 make it possible to increase the heat exchange surface of the element, here the support block 22, by which the heat is dissipated. These heat dissipation means 44 may be made by cooling fins.

  According to a preferred embodiment and illustrated in FIG. 14, conferring on the assembly a great compactness while promoting the dissipation of the heat produced notably by the LEb, the support block 22 comprises a plate 48 made of a thermally conductive material, in particular metal, having on one of its faces, said lower, the housing 36 (the side walls 38 projecting from said plate 48) and the other face, said upper, fins 50 arranged in perpendicular planes to said plate. The dimensions of the fins and their spacings are determined in order to optimize heat exchange.

  The means for generating a forced air flow 46 make it possible to create an air flow that substantially improves the dissipation of heat. Said means 46, such as a fan, may be on the lower and / or upper side of the support block 22.

  According to a preferred embodiment of the LEC lighting device, heat dissipation means 44, preferably in the form of vanes, are also provided at the lower face of the plate 48 of the support block, arranged on the and other housing 36. According to a variant illustrated in Figure 5, at least two vents 52 are provided to communicate between the inside and outside of the shell 14 to generate in combination with the ventilation means 46 a airflow from the outside of the shell inward to get fresh air in and from the inside to the outside of the shell to vent hot air. According to a preferred embodiment and illustrated in Figure 14, vents 52 are provided to communicate the housing 36 with the outside. These vents 52 combined with the means 46 of ventilation can generate an air flow promoting the delivery of fresh air inside the housing 36 and the evacuation of hot air. Advantageously, in the longitudinal direction of the device corresponding to the vertical plane containing the mast 12, the support block 22 comprises upstream and downstream of the housing 36 gills having fins arranged in the longitudinal direction, attached to the lower face of the plate 48 and connecting said plate 48 and the upstream and downstream side walls 38 of the housing 36, at least one vent 52 being provided at each downstream or upstream side wall 38 of the housing 36. Thus, according to this arrangement, an inlet of air on the lower face of the candelabra at which the luminous flux emerges, on one side of the housing 36, and an air outlet on said lower face of the other side of the housing 36. Thus, thanks to the means 46 of ventilation, we obtain a flow of air flowing on two outer faces of the housing 36 to obtain good heat dissipation at these faces and a flow inside the lodge 36 where the LEb are placed. This configuration provides optimal cooling to limit the temperature rise and the risk of deterioration of the various components. These different arrangements promoting the dissipation of heat contribute to increasing the life of the components of the device, including LEb, and thus to reduce maintenance costs. Furthermore, the fact of closing the housing using the light beam processing means 24 makes it possible to reduce the number of parts and facilitates the maintenance of the device. The lighting device 16 according to the invention comprises fixing means allowing the means 24 for processing the light rays emitted by the LEb to be held on the support block 22 and to close the housing 36. Advantageously, means sealing means 54, in particular a seal, are provided between the means 24 and the support block 22, situated at the periphery of the housing 36. The means 24 for processing the emitted light rays comprise means 56 for concentrating, because of the angle very open illumination of a LEb and 58 means of orientation of the light rays so that the illumination on the ground 20 corresponds to a lit area in accordance with standards. According to one embodiment, the means 24 are in the form of an optical element in one piece as illustrated in FIGS. 5 to 8 or of several superposed optical elements as illustrated in FIGS. 10 and 11. embodiment illustrated in FIG. 6, the optical element 24 comprises a network of concentrators (C1, C2,..., Ci,..., Cn) each disposed in line with an LEb. Each concentrator (Ci) of the optical element 22 corresponds to a solid element of frustoconical or paraboloidal shape, centered on a LEb and of a shape adapted to redirect and concentrate the light emitted by said LEb.

  As illustrated in FIG. 8, according to one embodiment, a concentrator (Ci) comprises a recess 60 in which an LEb (Li) is housed. The network of concentrators (C1, C2,..., Ci,..., Cn) is produced in a single block, in full matter of the optical element.

  In order to position as best as possible each concentrator (Ci) of the network of concentrators (C1, C2, ..., Ci, ..., Cn) in front of each LEb (Li) of the LEb matrix (L1, L2, .. ., Li, ..., Ln), means for positioning the optical element may be provided at the support block 22 or the support plate 20 of LEb. These positioning means may be made by at least one protruding element, such as a polarizer or locating, a boss, or any raised part of the support block 22 or a support plate 20 of LEb likely to provide accurate positioning when the implementation of the optical element 24. According to another embodiment illustrated in Figures 10 and 11, the means 56 of concentration are in the form of a plate 62 comprising on one of its faces (opposite to that opposite the LEb) protruding shapes in the form of corrugations 64, the ridges of which are arranged above the columns of LEb. These corrugations 64 comprise for each LEb a hollow concentrator 66 in the form of paraboloid opening via an opening 68 on the face of the plate 62 facing LEb. Each concentrator 66 comprises a reflective surface for optimally reflecting the light rays emitted by the LEb placed in said concentrator via the opening 68. According to the variants, the plate 62 may be made of a reflective material or only the surface of each concentrator can be coated with a reflective material.

  According to an embodiment illustrated in FIG. 7, the orientation means 58 of the optical element 24 can be made by a network of facets (F1, F2, ..., Fi, ..., Fn) corresponding to the LEb matrix (L1, L2, ..., Li, ..., Ln) of the lighting device. Each facet (Fi) of orientation of the optical element 22 is substantially centered on a LEb (Li) and is of suitable geometric shapes and inclination determined to orient the light beam concentrated by the concentrator (Ci) of the LEb (Li) corresponding. Thus, the facets 70 of orientation of the optical element 24 are shifted, such as plano-convex lenses, also called Fresnel lenses. The array of facets 70 of orientation (F1, F2,..., Fi,..., Fn) is produced in one single block, in full matter of the optical element 24. More particularly and as illustrated in FIG. 8 , each of the faces (Wire, Fi2,..., Fi j,..., End) of an orientation facet (Fi) is characterized by an angle of inclination aij with respect to the plane of the support plate 20 LEb, the plane (XY) in the figure, and by at least one radius of curvature Ri j. The light rays 72 coming from a concentrator (Ci) of an LEb (Li) are first refracted and / or reflected by the concentrator (Ci) corresponding to said LEb (Li) so as to be assembled into a beam of maximum luminous intensity, then refracted by the facet (Fi) orientation corresponding to said LEb (Li) so as to be directed and distributed optimally on the area to be illuminated. The optical element 24 is preferably made of polymer by injection / extrusion molding, but it can be made of any other material. For example, the optical element 24 can be made from a polycarbonate with a surface treatment, including a coating, allowing it to resist UV. According to a preferred variant and illustrated in FIGS. 10 and 11, the means 24 for processing the emitted light flux comprise, in addition to the concentrating means 56, orientation means 58 comprising reflection means 74 for orienting the light beams so as to to obtain a desired area of illumination or complies with the standards and means 76 of refraction to optimize the transmission of light rays outside by limiting parasitic reflections of light rays inwardly of the device, said means being stacked on each other from the support plate 20 to the outside. According to an embodiment illustrated in FIG. 10, the concentration means 56 comprise a plate 62 whose periphery comprises lateral walls forming a housing 78 in which the reflection means 74 and the refraction means 76 fit in succession. The dimensions of the side walls forming the housing 78 are adjusted to those of the housing 36. As shown in FIG. 11, the reflection means 74 comprise V-shaped mirrors 80 (in a section perpendicular to the LEC columns) whose tip of the V is oriented towards the LEC) and describes a ridge in line with the columns of LEC). As illustrated in FIG. 15, there are essentially three types of rays: the radii R1, mainly in the axis, which are not reflected by the concentrator but reflected by a mirror 80; the rays R2 which are neither reflected by the concentrator, or by a mirror, - the rays R3 which are reflected by the concentrator, some of which R3a are not reflected by a mirror and other R3b are reflected by a mirror. Advantageously, the dimensions of the concentrator and the mirrors and their relative positions are determined in such a way that the light rays emitted by a LEC) which are not reflected by the concentrator corresponding to said LEC) are also not reflected by a mirror. adjacent, not disposed above said LEC). This configuration makes it possible to avoid parasitic reflections and to adjust the distribution of radii R1 and radii R2. It is noted that the most energetic rays R1 are deflected to reach the farthest areas to be illuminated. Likewise, the dimensions of the concentrator and the mirrors and their relative positions make it possible to adjust the distribution between the radii R3a and R3b.

  The refraction means 76 comprise a wall 82 whose material makes it possible to transmit the light rays and comprising, at its inner face facing the LECs, corrugations 84 whose recesses or ridges are oriented in the direction of the LEC columns) and whose radius of curvature is adjusted so that the rays reflected by the mirrors 80 or by the concentrators have a zero or very low angle of incidence so that said rays are not reflected by said surface. Preferably, the outer surface of the wall 82 also comprises corrugations promoting the refraction of the light rays and limiting the reflection of the light rays inwardly of the device. According to one embodiment, the corrugations provided at the outer surface are not identical to those of the inner surface, so that the wall 82 does not have a constant thickness but areas with extra thicknesses improving the rigidity of said wall. Advantageously, the wall 82 comprises stiffeners oriented perpendicular to the corrugations in order to stiffen said wall. With the configuration illustrated in FIG. 11, an illumination zone as shown in FIG. 12 is obtained on the ground, with a substantially homogeneous luminance over the entire surface and an area in accordance with the regulations. Other functional modules can be added to the lighting device 16 according to the invention. A brightness measurement module, an activity measurement module and a communication module, just like those described in the French patent application No. 0650986, can make it possible to improve the management and the power supply of the LECs. lighting. For example, in the case of lighting a street or a public place, the activity measurement module and the brightness measuring means will make it possible to vary the light intensity provided by the device 16. lighting according to the need for lighting and ambient light. During the installation of said lighting device 16 on a lighting network comprising several lighting lanterns 10 or light point, the communication module can, thanks to a suitable communication protocol and more abundantly described in the French application. n 0650986, to collect and transmit from one light point to another to a collector information relating to activity measurements and brightness measurements but also relating to a possible defect of a lighting device.

  The maintenance of a lighting network, realized with the aid of the lighting device 16 according to the invention and equipped with a communication module and a brightness measurement module, is thus facilitated because it is sufficient to consult data collected by the collector for possible defective lighting devices 16.

  According to a preferred arrangement of the lighting device 16 LEb according to the invention, the management module and power supply, the brightness measurement module, the activity measurement module and the communication module are arranged on the face of the support plate 20 at which are reported the LEb. According to another characteristic, the lighting device may comprise at least one microcontroller providing a plurality of functions, such as, for example, the function making it possible to adapt the power supply automatically as a function of the LEb (s) used, or the function to manage the intensity of the lighting. Thus, the first function makes it possible to make the device compatible with the majority of LEbs that can be developed later and used in the lighting device. According to the invention, by measuring the luminous intensity emitted by the set of LEb, in particular by using a measurement module as described in French Patent Application No. 0650986, it is possible to adjust the power supply by means of the microcontroller in order to adapt it to the LEb used and installed in the lighting device. The microcontroller may comprise means for counting time from a time origin specific to the microcontroller and storage means enabling it to store the moment or times according to its time origin at which the ignition instruction or instructions or stop have been transmitted. Thus, the microcontroller can manage the variations in luminous intensity in a temporal manner by referring to its means of counting time and instants according to its time origin at which the start or stop instructions have been transmitted to it.

Claims (8)

  1. LEC lighting device), more particularly adapted for outdoor lighting, comprising a plurality of LECs (18) attached to at least one support plate (20), characterized in that said LEC lighting device) comprises on the one hand a support block (22) comprising a plate (48), one of whose faces forms the substantially plane bottom of a housing (36) in which is placed said at least one substantially flat support plate (20) of in order to cooperate closely with the bottom of the housing (36), said housing being closed by means (24) for treating the light rays emitted by the ECLs), and secondly, means (44) for dissipating heat provided at the other side of the plate (48) of the support block (22).   2. LEC lighting device) according to claim 1, characterized in that it comprises means (46) for generating a forced air flow.   3. LEC lighting device) according to claim 2, characterized in that it comprises at least two vents (52) for communicating the housing (36) with the outside which combined with the means (46) for generating a forced air flow makes it possible to generate a flow of air favoring the delivery of fresh air inside said housing (36) and the evacuation of the hot air.   4. LEC lighting device) according to one of claims 1 to 3, characterized in that the heat dissipation means (44) comprise fins attached to the upper surface of the plate (48) of the support block (22).   5. LEC lighting device) according to one of claims 1 to 4, characterized in that the support block (22) comprises upstream and downstream of the housing (36) gills having fins arranged in the longitudinal direction. , attached to the lower face of the plate (48) and connecting said plate (48) and the side walls (38) upstream and downstream of the housing (36), at least one vent (52) being provided at each downstream side wall or upstream (38) of the housing (36).   6. LEC lighting device) according to any one of claims 1 to 5, characterized in that it comprises means (42) for conduction of heat interposed between the support plate (20) and the support block (22).   7. LEC lighting device) according to one of claims 1 to 6, characterized in that the light ray processing means emitted by the ECL) comprise means (56) for concentration, means (58) 10 orientation of the light rays emitted by the LECs).   8. LEC lighting device) according to claim 7, characterized in that the means (56) of concentration comprise a plate (62) whose periphery comprises side walls forming a housing (78) in which are embedded the orientation means (58), the dimensions of the side walls being adjusted to those of the housing (56).