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
  • F21S2/00—Systems of lighting devices, not provided for in main groups F21S4/00 - F21S10/00 or F21S19/00, e.g. of modular construction
• • 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
  • F21V19/00—Fastening of light sources or lamp holders
  • F21V19/02—Fastening of light sources or lamp holders with provision for adjustment, e.g. for focusing
• • 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
  • F21V3/00—Globes; Bowls; Cover glasses
• • 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
  • F21V5/00—Refractors for light sources
  • F21V5/02—Refractors for light sources of prismatic shape
• • 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
  • G02B6/0096—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the lights guides being of the hollow type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
  • F21Y2103/00—Elongate light sources, e.g. fluorescent tubes

Definitions

• This invention relates to a linear lighting device provided with co-extruded internally prismatically scored screens.
• the present invention relates to a device of the above kind that enables a higher brightness under equal radiating energy conditions to be achieved together with a high illumination uniformity and a higher wear resistance, said device being advantageous for application to any linear lighting system, both of the optical guide type and of the continuous illumination type.
• linear lighting systems are largely utilized for efficient illumination of areas having a substantially linear geometry, such as highway and/or raiiroad tunnels as well as perimetral sections of areas protected for instance by fences.
• Such linear lighting systems can be of optical guide type in which a remote light source is used or of continuous light type, in which, for instance variable power fluorescent lamps are used.
• the devices utilized in linear lighting systems of optical guide type are substantially comprised of a conduct having a highly reflecting inner surface, in which a light beam emitted by an optical source, such as a light projector located at an end of said conduit, is propagated.
• the other end of the conduit can be provided with an optical light recuperator or it can be coupled to another similar device.
• One or more slits are provided along the side surface of said conduit and are equipped with suitable screens through which the emitted light is diffused to the area to be illuminated.
• the devices as used in linear lighting systems of continuous light type substantially differentiate with respect to those described for linear lighting systems of optical guide type owing to the light emission optical system that is formed by a linear light source, such as a fluorescent lamp extending in parallel relation to the axis of said conduit, while the first mentioned systems are provided with a light source iocated at an end of the conduit. All above devices have certain drawbacks.
• the screens are generally realized by utilizing suitable opaline materials, generally produced by molding or extrusion of homogeneous mixed raw compositions, so as to make them capable to filter the light, and this entails an average absorbance figure of about 60% of the radiating energy as well as a rapid wear thereof, with resultant increase both in the energy consumption and in the maintenance costs.
• a further drawback of the optical guide systems is due to the fact that the screens as utilized therein have a low uniformity figure and, therefore, do not satisfactorily fulfil the illumination uniformity requirements in respect of the area to be illuminated, as it is strictly necessary in highway tunnels, and this additionally results in a limitation of the maximum length of the conduits with consequent increase in the linear distribution density of the necessary projectors as well as in the lighting system costs.
• a still further drawback of the optical guide systems is due to the fact that the screens used therein have a unhomogeneous transversal photometric solid with respect to the axis of the conduit, thereby creating sharp shadows that could be erroneously construed as obstacles.
• the approach proposed by this invention is to be considered in this frame as it enables all above mentioned problems to be solved. It is the object of this invention, therefore, to furnish a device applicable in any linear lighting system and having a higher brightness under equal radiant energy conditions as well as a higher wear resistance, thereby enabling a reduction in power requirements and a reduction in the operation costs to be achieved. It is a further object of this invention to provide a device for optical guide type linear lighting systems having a high, both axial and transversal, illumination uniformity figure.
• a linear lighting device comprising a light propagation and/or emission conduit including one or more longitudinal light transmissive portions and one or more non-light transmissive portions, characterized in that said light transmissive portions are provided by corresponding longitudinal slits of a non-light transmissive tubular structure and comprise one or more screens of a co-extruded plastic material including a first inner layer of transparent plastic material, preferably a shock resistant polycarbonate or metacrylate material, and a second outer layer of a plastic material, preferably a polycarbonate or metacrylate material, suitably treated in order to make it opalescent, a prismatic scoring being provided in the inner surface of said transparent layer.
• a linear lighting device comprising a light propagation and/or emission conduit including one or more longitudinal light transmissive portions and one or more non- light transmissive portions, characterized in that said logitudinal non-light transmissive portions are realized by applying upon a light transmissive tubular structure corresponding longitudinal non-light transmissive elements, said light tansmissive tubular structure being made of a co- extruded plastic material including a first inner layer of transparent plastic material, preferably a shock resistant polycarbonate or metacrylate material, and a second outer layer of a plastic material, preferably a polycarbonate or metacrylate material, suitably treated in order to make it opalescent, a prismatic scoring being provided in the inner surface of said transparent layer.
• said prismatic scoring includes triangle shaped, longitudinal or transversal scores.
• this device can be modular. Further characteristics and embodiments of this invention are recited in the dependent claims.
• Figure 1 is a perspective exploded view of a first device according to this invention
• Figure 2 is a front elevation view of a detail of the device of Figure 1 ,
• Figure 3 is a cross-section side elevation view of the device of Figure 1 .
• Figure 4 is a cross-section side elevation view of a second device according to the invention.
• Figures 5a and 5b are cross-section front and side elevation views of the screen of a device according to Figure 4, and Figures 6a and 6b are cross-section front and side elevation views of the screen of a device according to Figure 1.
• a first embodiment of a device 1 according to this invention adapted for use in linear lighting systems of optical guide type, includes a conduit 2 formed by a substantially cylindrical, tubular structure 20, the inner surface of which reflects the light rays.
• Said tubular structure 20 is preferably made of aluminium and/or shock resistant polycarbonate and/or metacrylate and its inner surface is made light reflectant by deposition of a polished layer of aluminium with a purity figure > 99,95% or by means of a vacuum treatment or by means of a film of reflectant plastic material applied thereon, such as a film of mylar (R) .
• This tubular structure 20 has a longitudinal slit and a screen 3 through which the light can be outwardly diffused is arranged in said slit, as particularly shown in Figure 3. Said longitudinal slit together with screen 3 mounted therein forms the light transmissive longitudinal portion, while said tubular structure 20 forms the longitudinal non-light transmissive portion.
• a first end of conduit 2 is coupled with a projector having a bell shaped construction, preferably made by usual polymer materials as used in technical applications.
• Bell 4 houses a transversal parabolic diaphram 5, preferably made of a vacuum mirrored thermoplastic material, as well as a lamp 6 arranged upon a circular plate 7 for holding the electrical accessories 8 for power supply of said lamp 6.
• the parabolic diaphram 5 is adjustably arranged upon plate 7 in order to adjust its focus point with respect to lamp 6, preferably within a range ⁇ 4° with respect to the axis of lamp 6.
• Said lamp 6 can be, for instance, a high pressure, metal jodide and sodium, discharge lamp.
• conduit 2 is closed by an optical light recuperator closure member 9 having an inner light reflectant surface, preferably vacuum mirrored and protected by means of polymerized siiicone oils, with divergent parabolic optics.
• the above described device 1 is of modular design, so that one of or both ends of conduit 2 can be coupled to similar conduits 2, rather than to said projector or to said light recuperator closure member 9.
• Properly shaped gaskets 10 enable light tight couplings to be achieved between conduit 2 or bell 4 of said projector, respectively, and said light recuperator closure member 9 (or an other conduit 2).
• FIG. 4 shows a cross-section view of a second embodiment of conduit 2' of a device according to this invention, particularly intended for use in linear lighting systems of continuous illumination type.
• Said conduit 2' provided with a similar tubular, suitably shaped structure 20' and with a similar screen 3', as in the first embodiment, internally houses a fluorescent, linear lamp 11 , arranged at the focus point of a longitudinal parabolic partition 12.
• Lamp 11 is secured to a plate 13 also acting as a holder member for electrical supply accessories 14.
• closure member 9 (not shown) has an inner non-light reflectant surface.
• Screens 3 and 3' are made of co-extruded composite plastic material, preferably polycarbonate or metacrylate, which is made shock resistant by means of an integrally embedded reinforcement.
• This composite material consists of a transparent layer, with a thickness preferably in the range of 2 to 3 mm, having a film of a material co- estruded upon its outer surface and suitably treated in order to make it opalescent, for instance of a ultraviolet ray stabilized mixture, with a thickness in the range of 35 to 70 ⁇ m.
• This opalescent film diffuses the light transmitted therethrough thereby suppressing its glaring effects and, as a function of its thickness, as a function of its thickness, as a function of its thickness, it absorbs only within the range of 15% to 40% of the light power irradiated from the lamp.
• said opalescent film imparts brightness to the screen and assures a long useful life, more than 10 years, without incurring the typical yellowing effects of polycarbonate materials.
• Screens 3 and 3' are prismatically scored on their inner transparent surface layers. As it is shown in Figures 5a and 5b, a screen 3', as applied on devices 1 for use in continuous illumination systems, is preferably provided with longitudinal prismatic scoring.
• a screen 3 as applied on devices 1 for use in optical guide systems, is preferably provided with transversal prismatic scoring in order to enable a better control of the light rays generated by a remote source to be obtained.
• said screen 3 is adapted to collect any light rays scarcely divergent at the source and to control the multiple reflections generated in the above mentioned mirror treated conduit 2, thereby achieving a controlled and constant light in its transversal photometric solid, along a propagation path that can also be more than 10 metres long.
• Screen 3 which is provided with transversal prismatic scoring with preferably triangle cross-section scores, produces a homogeneous transversal photometric solid, with only light intensity variable as a function of the distance from the projector.
• said triangular cross-section shape of its scores is adapted to optimize the light collection capability as a function of the construction characteristics, such as the size, such as the size, of the devices 1 employed in optical guide systems.
• Screens 3 and 3' have a good uniformity figure, which is higher than all conventional screens, and, therefore, they are particularly advantageous for application to optical guides.
• a uniformity figure of expressed as the ratio of minimum to maximum illumination intensities is achieved in optical guides having a length of about 6.9 m.
• a conduit including a light transmissive tubular structure realized as said screen 3 (or 3'), upon which one or more non-light transmissive longitudinal elements are arranged.
• said light transmissive tubular structure is realized of a composite co-extruded plastic material, preferably polycarbonate or metacrylate, which is made shock resistant and, to this end, it is provided with a reinforcement.
• a composite co-extruded plastic material preferably polycarbonate or metacrylate, which is made shock resistant and, to this end, it is provided with a reinforcement.
• such material includes a transparent layer, preferably having a thickness in the range of 2 to 3 mm, upon the outer surface of which a film of a material is co-extruded upon being suitably treated in order to make it opalescent, for instance a mixture stabilized in respect of ultraviolet radiation, with a thickness in the range of 35 to 70 ⁇ m.
• Said light transmissive tubular structure has an intemaly, longitudinally or transversely scored, transparent surface layer.
• non-light transmissive elements realized of shock resistant aluminium, polycarbonate or methacrylate, for instance, are applied to said light transmissive tubular structure internally or externally or by co-extrusion.
• a mirroring treatment is applied to the non- light transmissive portions of the conduits themselves, in order to enable a multiple reflection propagation of the light radiation.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Light Guides In General And Applications Therefor (AREA)
• Optical Elements Other Than Lenses (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=11405282

Family Applications (1)

Country Status (4)

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• 1997
  • 1997-10-06 IT IT97RM000601A patent/IT1295414B1/it active IP Right Grant
• 1998
  • 1998-10-02 AU AU96432/98A patent/AU745328B2/en not_active Ceased
  • 1998-10-02 WO PCT/IT1998/000265 patent/WO1999018390A1/en active IP Right Grant
  • 1998-10-02 EP EP98950291A patent/EP1021678A1/en not_active Withdrawn

Non-Patent Citations (1)

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