Incandescent lamp with infrared filter
AssigneeU.S. Philips Corporation
InventorsFriedrich Hermann Raymund Almer, Heiner Kostlin
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Abstract
The thermal radiation which is emitted by an electric incandescent lamp is eliminated according to the invention by providing an incandescent lamp with a filter which transmits visible light and which reflects infrared radiation, which filter consists of an interference filter and a heavily doped metal oxide filter which is disposed at the side of the interference filter which is remote from the filament body.
Claims14
An electric incandescent lamp which comprises a filament body, a lamp envelope, a gas filling and a filter which is transparent to visible light and which reflects infrared radiation, said filter, being transparent to visible light and reflecting infrared radiation, comprise an interference filter and a heavily doped metal oxide filter with a plasma wavelength smaller than 1.4.mu.um, which is disposed at the side of said interference filter which is remote from the filament body.
Dependencies are inferred from the claim text.