Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21S—NON-PORTABLE LIGHTING DEVICES; SYSTEMS THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLE EXTERIORS
  • F21S8/00—Lighting devices intended for fixed installation
  • F21S8/08—Lighting devices intended for fixed installation with a standard
  • F21S8/081—Lighting devices intended for fixed installation with a standard of low-built type, e.g. landscape light
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V7/00—Reflectors for light sources
  • F21V7/0008—Reflectors for light sources providing for indirect lighting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V7/00—Reflectors for light sources
  • F21V7/22—Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors
  • F21V7/24—Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors characterised by the material
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V7/00—Reflectors for light sources
  • F21V7/22—Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors
  • F21V7/28—Reflectors for light sources characterised by materials, surface treatments or coatings, e.g. dichroic reflectors characterised by coatings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V9/00—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters
  • F21V9/04—Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters for filtering out infrared radiation
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
  • G02B6/0005—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being of the fibre type
  • G02B6/0006—Coupling light into the fibre

Definitions

• Lighting assembly by remote light source equipped with a thermal baffle, and candelabra incorporating such a lighting assembly
• the present invention relates, in general, to lighting by remote light source, for example of circulation or intervention areas, most often exterior, using luminaires, but not exclusively, luminaires with specific supports such as candelabras for public roads or industrial areas; they can also be luminaires integrated into supports and having a different function, such as in traffic tunnels or facade luminaires.
• the present invention relates to equipment for lighting from above a circulation or intervention zone, the light source of which is located near this zone (at maximum at height of man) and whose head located at a distance in height relative to this same area is optically connected to the light source.
• This type of equipment includes a light generator which injects a large amount of light energy into a light guide.
• the light emerging from the light guide at its other end is either reflected by a reflector or diffuser with a reflecting surface towards the area to be illuminated, or focused on this same area, by means of an appropriate optical system, depending on the envisaged application.
• the cold light source area as opposed to the hot light source constituted by the generator, can be constituted by a lateral portion of this guide.
• the light guides currently used for this kind of application are of several types: - bars or fibers based on quartz or silica: they absorb very little light energy, withstand very high temperatures, but are fragile and above all very expensive ;
• - plastic-based fibers or bars such as PMMA (polymethyl methacrylate). They are much less expensive than glass fibers, have much less loss in line than glass and are not fragile. They are also easy to implement.
• the light generator comprises a light source placed within an enclosure with reflecting surfaces, letting pass the infrared radiation, or even when the dichroic selector treatment of inside such an enclosure by the interposition, perpendicular to the beam emerging from the generator, of dichroic filters returning towards the interior of the generator the infrared radiation of the beam of light emerging from the latter
• the mirror is mounted on a support connecting a light generator to the light guide
• the support is shaped so as to recover from the mirror the converging part of a beam of light returned by an ellipsoidal reflector , at the focal point of which a light source is placed
• the mirror is mounted on the support so as to converge the visible part of this beam to a secondary focus located outside the cone of light recovered from the reflector and where the entrance to the light guide is placed
• the present invention therefore aims, in general, to improve the existing lighting assemblies and apparatuses presented above, in particular in terms of performance, while guaranteeing the integrity of their light guides
• a lighting assembly comprising a hot light source, a light guide intended to optically connect the hot light source and a cold source zone and a thermal baffle having a cavity extending from the source of warm light to the light guide, partially delimited by dichroic surfaces reflecting the visible and transmitting infrared, suitable for filtering light radiation emitted by the hot light source and intended to penetrate the light guide, characterized in that substantially cylindrical and reflective visible surfaces delimit the remaining part of the cavity and are adapted, in combination with the dichroic surfaces, to bring by reflection at the input of the light guide substantially all of a beam of diverging light emitted by the light source, while having subjected at least one reflection to the dichr surfaces oic at any light ray forming at the entrance of the light guide a angle with the axis of the guide less than the digital half-opening of the same guide
• the cavity is defined by two tubular sections of cylinder of the same circular section having internal surfaces reflecting the visible and whose longitudinal axes intersect at right angles and by a fixed dichroic mirror, which is arranged in look at the entrance surface of the baffle and at the intersection of the two tubular sections of cylinder
• the cavity is further defined by a third tubular section of cylinder with an internal surface reflecting the visible, present as a longitudinal axis intersecting at right angles a longitudinal axis of one of said two tubular sections of cylinder, so as to redirect the light beam in the axis of the light guide and having a circular section identical to that of said two tubular sections of cylinder
• a second dichroic mirror 'ic fixed, is arranged facing the first dichroic mirror and the intersection with the third tubular barrel portion and one of said two tubular sections cylinder,
• the first mirror is a plane mirror cutting at 45 ° the longitudinal axes of said two tubular cylinder sections; the second mirror is a plane mirror parallel to the first mirror and cutting at 45 ° the longitudinal axes of the two corresponding tubular sections of cylinder,
• tubular cylinder sections are made of aluminum and with polished internal surfaces
• tubular cylinder sections are made of ceramic and with smooth internal surfaces and coated with aluminum or silver;
• tubular cylinder sections are made of glass and have internal surfaces coated with aluminum or silver.
• FIG. 1 is a perspective view of a first embodiment of a thermal baffle according to the invention
• Figure 2 is a cross-sectional perspective view of Figure 1;
• Figures 3a and 3b are schematic views showing the path of light rays in a lighting assembly comprising a baffle as shown in Figures 1 and 2;
• FIGS. 4a and 4b are comparative diagrams of parts of the light beam actually injected into a light guide, representing sections IV-IV of the light beam of FIG. 3, - Figure 5 is a schematic view in vertical section with interruption of a street lighting candelabra incorporating a thermal baffle according to an embodiment of the invention;
• FIG. 6 is a schematic perspective view of the thermal baffle of Figure 5;
• Figure 7 is also a schematic view in cross section and in perspective of Figure 6;
• FIG. 8 is a schematic cross-sectional and flat view of Figure 6.
• the lighting assembly in which is incorporated a thermal baffle and which is shown in Figures 1, 2, 3a, 3b and 4b constitutes a first embodiment of the present invention, an application of which can be the lighting of operating fields, as mentioned above, or, more generally, the lighting of objects or passing through closed places ... All of lighting, marked 1 as a whole in the figure
• a hot light source S represented in the form of a point source, emitting a divergent beam of light, a light guide 2 and a thermal baffle 3.
• the thermal baffle 3 is shown in more detail in Figures 1 and 2 and will be described below. As regards the hot light source S and the light guide 2, they may be chosen to be identical to those which will be described below in support of FIGS. 5 to 8.
• the thermal baffle 3 shown in Figures 1 and 2 generally has a cavity 4 extending in the lighting assembly according to the invention and shown in Figure 3, from the hot light source S to the light guide 2.
• This cavity 4 is delimited in part by dichroic surfaces reflecting the visible and transmitting the infrared, adapted to filter light radiation emitted by the hot light source S and intended to penetrate into the light guide 2. More precisely, the cavity 4 is here defined by a set of substantially cylindrical surfaces reflecting the visible, in this case two cylinder sections 5 and 6 with internal surfaces reflecting the visible and a dichroic mirror 7 forming the aforementioned dichroic surfaces
• the two tubular cylinder sections 5 and 6 have identical circular sections and their respective longitudinal axes, 8 and 9 intersect at right angles, while the dichroic mirror 7 is fixedly arranged at the intersection of the two tubular sections of cylinder 5, 6 More precisely, as can be seen in FIG.
• the dichroic mirror 7 is, HERE, places at the intersection of the longitudinal axes 8 and 9 and cuts these at 45 °
• the part of the thermal baffle 3 formed by the cylinder sections 5 and 6 has the external shape of a prism with a triangular section, each of the tubular cylinder sections 5 and 6 opening out by one of its lateral faces forming between them a right angle
• the dichroic mirror 7, for its part, is carried by the face of the prism joining the two preceding ones and has a communicating dichroic surface, through an opening made in the corresponding face of the prism, with the tubular sections of cylinder 5 and 6
• the prismatic part of the thermal baffle 3 is made of reflective metal, HERE aluminum, the internal surfaces having been polished. It will be noted that in other embodiments, ia prismatic part may be made of ceramic, the internal surfaces then being made smooth and coated with aluminum or silver, or alternatively be made of glass with internal surfaces coated with aluminum or silver
• the dichroic mirror 7 is here a mirror reflecting the visible radiation (wavelength between 400 and 700 nm) and transmitting all the rest, or almost all the rest, of the spectrum of the beam incident on the mirror
• UV radiation can, like infrared radiation, also be harmful, in the sense that it contributes to the premature aging of an optical bar of a light guide, when this bar is in plastic material
• dichroic reflecting surfaces which transmit the entire spectrum of the light beam, except the visible part
• Such a mirror can be obtained by dichroic selector treatment, for example by depositing multi-electric layers on a glass plate
• the cylindrical surfaces of the cylinder sections 5, 6 and the flat surface of the plane dichroic mirror 7, delimiting the cavity 4, are formed and arranged continuously and in such a way. so that they bring, in combination, by reflection at the input of the light guide 2, substantially the entire divergent light beam emitted by the light source S, while having subjected at least one reflection to the dichroic surface a any light ray forming at the input of the light guide 2 an angle with the axis of the guide less than the digital half-opening of this same guide 2
• FIG. 3 shows a beam of light emerging from a point source of hot light S, thanks to two limiting rays 13, 14 of which the path is represented by arrows Furthermore, this same figure 3 shows, in hatched form, the part of the light beam which will be effectively injected into the light guide 2, if the dichroic mirror 7 was used alone without cylindrical surfaces reflecting the visible, of the type provided by the cylinder sections 5, 6
• Figures 4a and 4b represent the gain in light beam share which will be effectively injected into the light guide 2
• the hatched areas represent the part of the light beam available at the input of the thermal baffle 3 which will be effectively injected into the guide
• the non-hatched areas of each of these figures 4a and 4b represent the part of the light beam which will be lost
• the part of the light beam which will actually be injected into the light guide 2 is significantly greater when a cylindrical guidance is implemented using cylindrical surfaces reflecting the visible (FIG. 4b) that in the case where a dichroic mirror is used alone ( Figure 4a)
• Figure 4a In practice, in the implementation of a cylindrical guide, 35% more light beam is recovered which will actually be injected into the light guide 2
• the lighting assembly shown in FIG. 5 is integrated into a street lighting candelabra, identified as a whole.
• This candelabra is also to be considered by way of example and non-limiting application of the assembly. of the present invention and mainly comprises two sub-assemblies. an elongated part or barrel 25, fixed to the ground, extending from the latter upwards, and an upper part or head 20 mounted at the free end of the barrel 25
• the post 25 of the candelabrum incorporates a lighting assembly 30 according to the second embodiment. More precisely, this lighting assembly 30 comprises, first of all, a light generator 31 arranged in the lower part or foot of the barrel 25 and fixed on a support 32, itself fixed to the foot of the barrel in a manner not shown The foot of the barrel 10 is in practice also equipped with an inspection hatch, not shown HERE
• the lighting assembly 30 also includes a light guide 33 intended to optically connect the hot light source constituted by the generator 31 and a zone forming a cold light source.
• the beam of cold light emerging from the guide light is returned to the ground by a lantern fitted with a reflector and constituting the head 20
• the head 20 may be formed by any other suitable diffuser, and in particular a diffuser such as that described in the International patent application WO-95/10792 cited above
• the light guide 33 being constituted by an optical bar, the latter could simply be pointed, without the use of no diffuser, to an area to enhance, or be connected to a network of optical fibers, or even be frosted on all or part of its lateral surface, at its free end, for example for lateral illumination
• the light guide 33 is, in fact, because of its particularly advantageous characteristics explained above, consisting of an optical bar 34 of plastic material, such as PMMA, a few centimeters in diameter (generally between 3 and 6 cm) surrounded by an air sheath 35 whose thickness is HERE a few millimeters over most of its circumference, and protected by a mechanical protection 36
• This mechanical protection 36 is HERE IN THE form of a cylindrical tube
• Spacers 37 are arranged between the mechanical protection 36 and the optical bar 34 to center and tighten the latter.
• the lighting assembly 30 comprises, in a particularly advantageous manner, an optical baffle 40 interposed between the generator 31 and the light guide 33. Its characteristics will be described in support of FIGS. 6 to 8.
• the generator 31 comprises an enclosure 43 with reflective internal surfaces which comprises:
• a light source 45 similar to a point source, such as a short arc discharge lamp, of the metal iodide type, approximately placed at the first focal point F-, located in this half-ellipsoid portion; and
• annular hemisphere portion 46 covering from its base the half-ellipsoid portion 44, centered on said focal point F 1 t with an axis coincident with the major axis 48 of the ellipsoid defined by said half-ellipsoid portion, and having an opening at its top of axis also coincident with said major axis 48.
• Such an enclosure 43 may be surrounded by a heat shield and include a housing containing a socket for the lamp, the housing itself being tightly connected to a ballast connected to an electrical energy supply network.
• the thermal baffle 40 comprises two dichroic mirrors 107 and 107 ′ planes and parallel.
• the cavity 104 of the thermal baffle is here defined by three tubular cylinder sections 105, 106 and 113 having the same circular section.
• the tubular central cylinder section 113 extends along the longitudinal axis 114 of the thermal baffle 40 and is connected at each of its ends to one of the other two tubular cylinder sections 105, 106.
• the respective longitudinal axes 108, 109 of the tubular sections of cylinder 105, 106 are each perpendicular to the axis 114 and therefore parallel to each other
• tubular cylinder sections 105, 106 extend in parallel directions, but however in opposite directions. Unlike the first embodiment, the circular entry surfaces
• Each of the mirrors 107, 107 ′ cuts, on the other hand, at 45 °, two perpendicular longitudinal axes of two respective tubular sections of cylinder and is at the intersection of these corresponding axes
• a first 107 of these two mirrors is arranged so as to obliquely cut the major axis 48, also constituting the axis of the beam of light emerging from the reflecting enclosure 43, with an angle of 45 °
• One of the faces of the mirror 107 is, here, facing the surface 110 and the other is turned towards the exterior of chicane 40
• the first mirror 107 intercepts the light beam, returns it by reflection to the second mirror 107 'which itself returns it by reflection in the direction of the entry surface 49 of the light guide 33 so reorient the light beam along the axis of the latter, which is parallel to the major axis 48
• the light beam produced by the light generator 31 is deflected from its path on either side of the major axis 48 and subjected to a zigzag path in the baffle 40, the entire visible part of the beam of cold light incident on the entry surface 49 having been subjected to reflection and the infrared radiation having been removed from the useful radiation by transmission
• the second mirror 107 ' is HERE also dichroic, in order to evacuate any residual infrared radiation that may possibly be reflected by the first mirror 107
• the axes marked 48 and 109 are in this embodiment in the coaxial position.
• the thermal baffle 40 does not extend in one piece the reflective enclosure 43 .
• Those skilled in the art will, in this regard, be able to produce the means of fixing and maintaining such a baffle 40 on the reflective enclosure 43 or the generator 31, but also within a candelabra barrel, just as it will be able to produce the means for fixing and maintaining the light guide 33 within this candelabrum barrel In the case of candelabrum 1 in FIG.
• the light guide is fixed and maintained at its upper end in the candelabrum barrel using perforated brackets 51, while its base is disposed next to a porthole 52 surmounting the thermal baffle 40
• This porthole 52 is made of a transparent material treated anti-reflective to prevent any light loss
• This porthole 52 also makes it possible to close the reflective enclosure assembly 43 - baffle the rmique 40 to isolate the light guide 33 from the ambient heat prevailing in this enclosure 43
• the reflecting internal surfaces of the enclosure 43 may also be dichroic, reflecting in the visible range and transmitting radiation infrared
• the heat leaving the reflecting enclosure 43 will then be stopped by the thermal butcher mentioned above, then evacuated by chimney effect through the tubular space constituting an air passage, delimited by the barrel 25 of the candelabrum around the light guide 33. It is also the same for the heat rejected by the dichroic mirrors 107 and 107 '.
• the light guide 33 is curved at its base extending the baffle 40 and straight over the rest of its length, extending substantially along the axis of the barrel 25 of the candelabrum 1, making it possible to catch up with the lateral offset of the entry surface 49 induced by the thermal baffle 40, while ensuring an optimal chimney effect.
• the mirror 107 which cuts the long axis 48 with an angle of 45 ° can of course be placed in front of the second focal point F 2 defined by the concave portion of semi-ellipsoid, in the direction of the first focal point F ⁇ while the reflecting surface of the other mirror 107 ′ will be placed in the vicinity of the focal point of concentration of the light beam reflected by the mirror 107.
• the virtual point of concentration of the light beam incident on this surface can be brought closer to the input surface 49.
• a light guide 33 of smaller section, and therefore less bulky, can thus be used.
• Such a lighting assembly thus proves to be particularly efficient in terms of visible light flux obtained at its exit, but also proves to be inexpensive and easy to produce.
• thermal baffle Other geometries of thermal baffle are obviously possible.
• the second mirror 107 ′ may be replaced by a curved mirror.
• a thermal baffle may be produced, all of the internal surfaces of which will be dichroic.
• the dimensions and shapes of the baffles will of course always be adapted to the characteristics of the guides and light sources to be used. It is also possible to produce a lighting assembly, in which the thermal baffle will be an integral part of the light generator, by extending, in one piece, the reflective surfaces of the enclosure 43. As regards the optimization of the dimensions and forms of the thermal baffle and the light generator, reference may also be made to the international application WO-95-10792 cited above.

Applications Claiming Priority (3)

Publications (1)

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ID=9482498

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Family Cites Families (8)

• 1995
  • 1995-09-13 FR FR9510720A patent/FR2738622B1/fr not_active Expired - Fee Related
• 1996
  • 1996-09-12 WO PCT/FR1996/001408 patent/WO1997010471A1/fr not_active Application Discontinuation
  • 1996-09-12 EP EP96931118A patent/EP0791156A1/de not_active Ceased
  • 1996-09-12 AU AU69921/96A patent/AU6992196A/en not_active Abandoned
  • 1996-09-12 HU HU9800519A patent/HUP9800519A2/hu unknown

Non-Patent Citations (1)

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