Patent ID: 6476556
Filing Date: 2002-11-05
Classification: G02B,H01J

Abstract:
An electric lamp comprising a light-transmitting lamp vessel (1) in which a light source (2) is arranged,wherein at least a portion of the lamp vessel (2) is provided with an interference film (5) for allowing passage of visible-light radiation and reflecting infrared radiation, wherein the interference film (5) comprises layers (L, H) which are arranged such that a first layer (L) of a material having a first refractive index alternates with a second layer (H) of a material having a second refractive index, wherein the second refractive index is comparatively high as compared to the first refractive index, characterized in that, in the wavelength range from 400 to 760 nm, the interference film (5) has a transmittance, on average, of at least 90%, and in the wavelength range from 800 to 2200 nm, the interference film (5) has a reflectance, on average, of at least 75%.