| 摘要 |
The electric lamp comprises a lamp vessel ( 1 ) which is transparent to visible light and which accommodates a light source ( 2 ). The lamp vessel ( 1 ) is covered with a combination of a light-absorbing medium ( 6 ) and an optical interference film ( 5 ) comprising layers of alternately a first layer of a material with a comparatively high refractive index and a second layer of silicon dioxide. According to the invention the maximum reflection R<SUB>max </SUB>of the interference film ( 5; 15 ) lies in the range from 0.50<=R<SUB>max</SUB><=0.90 and in that the variation in the reflection R of the interference film ( 5; 15 ) in the wavelength range from 400<=lambda<=690 nm ranges from 0.0 to R<SUB>max </SUB>in order to obtain an overall color neutral appearance. In operation, the electric lamp according to the invention emits colored light in the transmission mode and has a substantially color-neutral appearance in the off state.
|
