Incandescent lighting

• US 20040232837A1
• Filed: 10/29/2003
• Published: 11/25/2004
• Est. Priority Date: 07/20/2002
• Status: Abandoned Application

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: King, Douglas Beverley Stevenson
• Application Number:
  US10/476,305
• Publication Number:
  US 20040232837A1
• Time in Patent Office: Days
• US Class Current: 313/578
• CPC Class Codes: H01K 1/04 characterised by the material thereof
• CPC Class Codes: H01K 1/14 characterised by the shape

Abstract

An incandescent electric lamp having a tungsten filament embedded in tightly-packed layers of optically transparent, thermally insulating particles of substantially consistent size and shape and surrounded by an optically transparent, infra-red reflective coating, to provide a high efficiency, cool lighting system.

Claims

1. An incandescent electric lamp comprising an incandescent filament embedded in a porous matrix formed from a plurality of particles of a thermally insulating and optically transparent material, the particles being of substantially consistent size and/or shape.

2. An incandescent electric lamp according to claim 1 wherein the porous matrix comprises a plurality of similarly sized interstices between adjacent particles.

3. An incandescent electric lamp according to claim 2 wherein the mean sizes of the particles and/or of the interstices are a proper fraction or a multiple of the wavelength of a desired part of the optical spectrum.

4. An incandescent electric lamp according to claim 1, wherein the porous matrix is enclosed in an optically transparent casing.

5. An incandescent electric lamp according to claim 4 wherein the casing has an optically transparent, infra-red reflective surface.

6. An incandescent electric lamp according to claim 1, wherein the particles are beads.

7. An incandescent electric lamp according to claim 1, wherein the matrix comprises particles of two consistent sizes, a plurality of particles of a first smaller size adapted to fit snugly in the interstices between tightly packed particles of a second, larger size.