Patent ID: 8436519

Claim:
An incandescent lamp comprising: a filament that, when heated, emits visible light and infrared light; an envelope enclosing the filament and including an inner surface facing toward the filament and an outer surface facing away from the filament; and a coating system deposited on the envelope and including a dielectric coating configured to transmit a substantial portion of visible light emitted by the filament and to reflect a substantial portion of infrared light emitted by the filament, a transparent conductive coating located on the side of the dielectric coating opposite the filament, wherein the transparent conductive coating is configured to transmit a substantial portion of visible light emitted by the filament and transmitted through the dielectric coating and further is configured to reflect a substantial portion of infrared light emitted by the filament and transmitted through the dielectric coating, and first and second oxygen diffusion barriers located on opposite sides of the transparent conductive coating, for preventing oxygen from reaching the transparent conductive coating, wherein the first and second oxygen diffusion barriers both comprise silicon nitride.