| 摘要 |
<p>The electric lamp comprises a lamp vessel (1) which is transparent to visible light and 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 layers of silicon dioxide and layers of a material with a comparatively high refractive index (e.g. ZrO2). According to the invention, the reflection R of the interference film (5) changes from 0.60 ≤ R ≤ 0.95 to 0.40 ≤ R ≤ 0.65 with a step ΔR in the range 0.2 ≤ ΔR ≤ 0.45, in a wavelength range 0.95×λtr ≤ λ ≤ 1.2×λtr. 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.</p> |
