Backlighting unit especially for liquid crystal display, includes plane plastic panel with side lighting tubes adjacent to heat-resistant plastic diffusers

摘要

The unit (T) is a plane resin panel with optically-transmitting section (3). Light enters the sides from the sources (L) and is radiated from the opposite surfaces. At the sides, optical diffusers (5) are included, made of a second resin, extending in at right angles to the side surfaces, along the unit. An Independent claim is included for the method of manufacture. The transmitting section is injection molded, followed by the diffuser, and they are fixed together. Preferred features: The first resin is transparent, the second, diffusive. The diffuser runs along the side or is held on a section (6) unitary with the light transmitting section. Diffuser thermal resistance exceeds that of the transmitting section. The second resin contains about 2-5 wt% of light scattering material. The thickness of the light scattering section is given by 10.1 x EXP (-1.406t) = T = 56.3 x EXP (-1.569t). The transmitting section and diffusive section are made one-piece by injection molding, the second resin differing from the first. Variants based on the foregoing principles are described.