Patent ID: 7453190

Claim:
An electric lamp comprising a light-transmitting lamp vessel in which a light source is arranged, said electric lamp comprising a light-absorbing medium exhibiting a spectral transition at a wavelength λ tr in the visible range, at least a part of the lamp vessel being provided with an interference film , wherein in a wavelength range 0.95×λ tr ≦λ≦1.2×λ tr , a reflection R of the interference film changes from 0.60≦R≦0.95 to 0.40≦R≦0.65 with a step ΔR in a range 0.2≦ΔR≦0.45, wherein the reflection R has a first reduced level and a second reduced level beginning substantially from the wavelength λ tr , the first reduced level being substantially constant for approximately 100nm more than the wavelength λ tr .