| 摘要 |
PURPOSE:To provide satisfactory characteristics in visibility and quality by restraining, to a maximum possible extent, problems in optical properties due to the fact that a light emitted from a semiconductor light emitting device exceed the predetermined half width. CONSTITUTION:An optical filter layer 10 for implementing narrow-band wavelength selection is formed on a surface 2a on a light emitting side of a semiconductor light emitting device 1. It is preferred to form an optical filter layer 10 using transparent films 8 and 9 of two or more layers of different refractive indexes. Specifically, the semiconductor light emitting device 1 is composed of a N-type semiconductor layer 3, a light emitting layer 4 and a p-type semiconductor layer 5 which are formed on the surface of a transparent sapphire substrate 2. The optical filter layer 10 is formed on the back surface 2a of the sapphire substrate 2. To provide satisfactory effects, the crystal layers 3, 4 and 5 of the semiconductor light emitting device 1 are formed in a multilayer structure emitting a blue-color light. |
