Lighting apparatus for illuminating accessible areas

1. Lighting apparatus, comprising:

a casing moulded from an electrically isolating and thermally conductive plastics material;

a plurality of light emitting diode (LED) devices configured to emit light in response to receiving electrical power; and

a plurality of overlapping metallic assemblies, wherein each one of said metallic assemblies provides electrical power to a respective one of said LED devices, conducts heat from its respective LED device to said casing, and is directly supported by said casing, wherein each of said metallic assemblies includes an inclined bracket, having a base portion attached to said casing, an inclined portion extending from said casing and a raised portion for supporting an LED subassembly.

2. The lighting apparatus of claim 1 , configured to provide security lighting within said accessible areas, wherein said LED devices are individually replaceable so as to optimise the wavelength of emitted light for remote viewing purposes.

3. The lighting apparatus of claim 2 , selectively operable with light emitting diodes in the infra-red spectrum, the visible spectrum, a portion of said visible spectrum and the ultra violet spectrum.

4. The lighting apparatus of claim 1 , wherein said casing is moulded from at least one selected from the group comprising: E2 thermally conductive liquid crystalline polymer; E3603 thermally conductive polyamide 4,6; E3605 thermally conductive polyamide 4,6; E4501 thermally conductive polycarbonate; E405 thermally conductive polycarbonate; E4507 thermally conductive polycarbonate.

5. The lighting apparatus of claim 1 , wherein said plurality of LED devices are divided into groups, wherein LED devices within each of said groups are electrically connected in series and said serially connected groups are electrically connected in parallel.

6. The lighting apparatus of claim 5 , wherein said groups are arranged in a substantially regular matrix.

7. The lighting apparatus of claim 1 , wherein an inclined bracket is attached to said casing for each of said LED devices.

8. The lighting apparatus of claim 7 , wherein a first attached inclined bracket is next to a second inclined bracket in a matrix, the raised portion of the second inclined bracket is above the base portion of the first inclined bracket, such that said base portion of said first inclined bracket lies between said raised portion of said second inclined bracket and the casing.

9. The lighting apparatus of claim 1 , wherein said LED sub assembly includes:

an inner electrically conductive element having an LED wafer mounted thereon to provide thermal conduction of heat away from the LED wafer and a first electrical connection to said LED wafer;

a coaxial insulating element of a thermally conducting plastics material moulded around the inner electrically conductive element; and

a coaxial outer conductive element electrically connected to the LED wafer.

10. A method of fabricating lighting apparatus, comprising the steps of:

arranging a plurality of overlapping inclined metallic brackets within a mould;

moulding a casing around said inclined metallic brackets to support said inclined metallic brackets, wherein said casing is moulded from an electrically insulating and thermally conductive plastics material;

locating individually supported light emitting diode (LED) devices within each of a respective one of said inclined metallic brackets, wherein each of said inclined metallic assemblies includes an inclined bracket, having a base portion attached to said casing, an inclined portion extending from said casing and a raised portion for supporting an LED subassembly.

11. The method of claim 10 , wherein said individual LED devices are individually replaceable to adjust the wavelength of the light emitted therefrom.

12. The method of claim 11 , wherein LED devices are operable within the infra-red spectrum, the visible spectrum and the ultra-violet spectrum.

13. The method of claim 10 , wherein the casing is moulded from at least one selected from the group comprising: E2 thermally conductive liquid crystalline polymer; E3603 thermally conductive polyamide 4,6; E3605 thermally conductive polyamide 4,6; E4501 thermally conductive polycarbonate; E405 thermally conductive polycarbonate; E4507 thermally conductive polycarbonate.

14. The method of claim 10 , wherein the individually supported light emitting diode devices are divided into groups, wherein LED devices within each of said groups are electrically connected in series and said serially connected groups are electrically connected in parallel.

15. A method of supplying electrical power to each of a plurality of light emitting diode (LED) devices contained within a lighting apparatus, comprising the steps of:

defining a plurality of inclined metallic brackets each having a base portion, an inclined portion and a raised portion, wherein said base portion includes a lower hole and said raised portion includes an upper hole with a diameter greater than said lower hole;

moulding a casing around inclined metallic brackets to establish one or more groups, in which the brackets contained within each group are serially connected and a lower hole of a first bracket in a group is located directly below an upper hole of a second bracket in the same group, thereby defining aligned holes;

removing the moulded casing from a mould, in which the moulded casing when so removed supports said brackets and is electrically isolating and thermally conductive so as to dissipate heat generated by the LED devices;

inserting LED sub-assemblies through respective aligned holes, wherein each of said LED sub-assemblies includes an inner conductive element, a co-axial insulating element, a co-axial outer conductive element and an LED wafer mechanically and electrically connected to said inner conductive element to facilitate electrical transmission and heat transmission, and electrically connected to said outer conductive element; such that:

an electrical path is provided from a raised portion of a first inclined bracket to an outer conducting element, through the LED device to an inner conducting element and from said inner conducting element to a base portion of a second inclined bracket.

16. The method of claim 15 , wherein the lower holes are tapped and threaded lower ends of respective inner conductive elements are threaded.

17. The method of claim 15 , wherein said co-axial insulating elements are secured within respective upper holes.

18. The method of claim 15 , wherein a plurality of groups of LED devices are included and said groups are electrically connected in parallel.

19. The method of claim 15 , wherein electrical power is received from a mains supply, including the steps of rectifying said mains supply and controlling power input to the LED devices by a process of pulse width modulation.