Lighting apparatus for hazardous areas

Abstract

A lighting apparatus for hazardous environments, comprising at least one substantially point-like source of light, and a housing structure for said at least one substantially point-like source of light, defining at least a triple barrier protective encapsulation to seal and insulate said at least one source of light from the environment, wherein said triple barrier protective encapsulation is at least partially optically transmissive to enable light propagation from said at least one source of light to the environment at predefined wavelengths.

Claims

1. A lighting apparatus for hazardous environments, comprising: at least one substantially point-like source of light, and a housing structure for said at least one substantially point-like source of light, defining at least a triple barrier protective encapsulation to seal and insulate said at least one source of light from the environment, wherein said triple barrier protective encapsulation is at least partially optically transmissive to enable light propagation from said at least one source of light to the environment at predefined wavelengths.

2. The apparatus of claim 1, wherein the triple barrier encapsulation comprises a plurality of hollow, nested elements.

3. The apparatus of claim 1, wherein the housing structure comprises an optically transmissive, outer element to provide a first barrier of insulation against the environment.

4. The apparatus of claim 3, wherein the outer element incorporates a functional coating, optionally conductive coating.

5. The apparatus of claim 1, wherein the housing structure comprises an optically transmissive, inner element to provide a second barrier of insulation against the environment.

6. The apparatus of claim 1, wherein the triple barrier protective encapsulation comprises a number of optically functional features for controlling light, said features optionally comprising surface relief structures.

7. The apparatus of claim 6, wherein the features have at least one optical function selected from the group consisting of: light directing, collimation, diffusing, coloring, scattering, and distribution function.

8. The apparatus of claim 1, wherein the triple barrier protective encapsulation comprises at least one material selected from the group consisting of: glass, ceramic, plastic, polymer, and substantially UV resistant material.

9. The apparatus of claim 1, wherein the housing structure comprises an optically transmissive, optionally molded, core material element encapsulating said at least one substantially point-like source of light to provide a third barrier of insulation against the environment, the core material optionally supporting said at least one substantially point-like source of light.

10. The apparatus of claim 9, wherein the core material comprises at least one material element selected from the group consisting of: elastomer, silicone, acrylic, polyurethane, olefin based elastomer, and polymer.

11. The apparatus of claim 9, wherein the core material element is configured for color tuning or light extraction.

12. The apparatus of claim 1, comprising at least one closing element, to hermetically seal the housing structure or an element within the housing structure.

13. The apparatus of claim 12, wherein the closing element includes a number of electrically conductive portions or elements for supplying power to said at least one substantially point-like source of light.

14. The apparatus of claim 1, wherein said at least one substantially point-like source of light includes a LED (light emitting diode).

15. The apparatus of claim 1, wherein said at least one substantially point-like source of light includes a LED strip of a plurality of LEDs.

16. The apparatus of claim 1, comprising a cooling element for said at least one source of light.

17. The apparatus of claim 3, wherein the outer element is cylindrical.

18. The apparatus of claim 5, wherein the inner element is cylindrical.

19. The apparatus of claim 5, wherein a gap of gaseous substance such as air remains between the inner and the outer elements.

20. The apparatus of claim 12, wherein the closing element is a lid, flap, or end cap.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Next the invention will be described in greater detail with reference to the accompanying drawings, in which:

[0028] FIG. 1 illustrates an embodiment of a lighting apparatus in accordance with the present invention.

[0029] FIG. 2 illustrates the internals of the embodiment of FIG. 1 with the cover element removed.

DETAILED DESCRIPTION

[0030] FIG. 1 illustrates, by way of example only, an embodiment of a lighting apparatus 102, or ‘light fixture’ or ‘luminaire’, in accordance with the present invention. On the right at 110, a cross-sectional view along line A-A is shown. The apparatus 102 comprises housing with an outer element 7 essentially defining in this example a symmetrical cover tube that may optionally be electrically conductive to fulfil ‘Ex’-area utilization criteria and requirements, for instance.

[0031] Base material of the outer tube 7 may include e.g. transparent glass, ceramic or polymer with or without special conductive coating. The used materials are preferably UV (ultraviolet) resistant.

[0032] Both end areas of the cover tube 7 are preferably hermetically sealed, optionally with an end cover such as a lid or cap possibly also carrying electrical rod or wired contacts 6 to enable energizing the light sources and potential related control electronics within the housing, essentially organized e.g. as a LED (light-emitting diode) strip 4 in this particular embodiment. The end cover may be, after manufacturing, permanently sealed or remain removable/operable, with or without tools, to facilitate serviceability of the internals of the luminaire.

[0033] FIG. 2 illustrates the internals of the embodiment of FIG. 1 with the tubular outer cover element 7 removed.

[0034] Within the hollow space defined by the cover element 7, the inner element, preferably being or comprising a tube 1, is disposed. It may include e.g. transparent glass, ceramic or plastic material 2, which may inherently have or be specifically configured to carry optically functional characteristics for light control. It may exhibit optical management features such as three dimensional relief forms on the (inner/outer) surface and/or as embedded within the material for purposes such as light directing, collimation, diffusing, coloring (e.g. from white light), and/or generally establishing a desired light distribution. These functionalities can be fully integrated with the tube and/or assembled at close proximity thereto, either on the inside or outside. The optical features can be realized by refractive and/or diffractive surface reliefs, volume/cavity optics containing e.g. sub-micron or micron scale profiles, or volume scattering features. In addition to or instead of such features of the inner tube 1, in some embodiments the cover element 7 may incorporate similar characteristics.

[0035] Inside the tube 1, at least one light source is found e.g. in the form of one or a plurality of LED strips 4. The LEDs may be traditionally packaged ones or e.g. OLEDs (organic LED). Alternatively or additionally, some other applicable light sources could be applied. Source-emitted or finally outcoupled color is typically white, but basically any color/wavelength is possible including IR radiation. Light source may be provided with related substrate, control electronics and/or other assisting elements such as strip or sheet for cooling purposes.

[0036] Light source 4 is preferably fully encapsulated and sealed by a covering hermetic barrier (core) element or layer 3 that is sufficiently transparent with high enough transmittance according to the utilized criteria depending on the embodiment, and may implement color tuning and/or improve light extraction from the source 4, for example. Suitable materials and shapes, optionally reliefs, may again be used for optimized light transmission and control together with hermetic sealing and protection function. Encapsulating material may especially include silicone, polyurethane, acrylic, olefin based elastomer, or polymer, i.e. applicable material to avoid electric short circuits, sparks, and/or moisture contacts. The material may be solid or gel-like, for instance. It may be moldable, extrudable and/or curable during the manufacturing of the lighting apparatus.

[0037] The inner tube 1 may be finally sealed with permanent or detachable/operable (with or without tools) end covers such as caps 5a, 5b, which may contain e.g. rod or wired contacts for electrically connecting the light source 4 to the external power supply.

[0038] The caps of the inner 1 and cover (outer) 7 barrier tube elements may be shared or dedicated depending on the embodiment. The caps may lock the inner tube 1 in place within the cover tube 7.