| 摘要 |
Provided is an illumination device having no moving parts, small in scale, and capable of achieving excellent gradation lighting over a wide surface without impairing the aesthetics thereof. Extending approximately in parallel are the long direction axes of a first substrate whereon first light sources for emitting a first light flux are mounted, and a second substrate whereon second light sources for emitting a second light flux are mounted. The chromaticity of the first light flux and the chromaticity of the second light flux are different. The illumination device satisfies the following formulae when the respective angular intensity distributions for the first light flux emitted from a first optical system and the second light flux emitted from a second optical system are acquired in a plane that is orthogonal to the axis of the first substrate or the second substrate: PS1 < PCS < PS2 (1) 0.2 ≤ SCS/PK1 ≤ 0.9 (2) 0.2 ≤ SCS/PK2 ≤ 0.9 (3) where PS1 represents the angular position at which the intensity is highest in the first light flux, PK1 represents the intensity thereat, PS2 represents the angular position at which the intensity is highest in the second light flux, PK2 represents the intensity thereat, PCS represents the angular position of an intersection on the angular intensity distributions of the first light flux and the second light flux, and SCS represents the intensity thereat. |
