High luminous efficiency Mercury-free flat light source for LCD BLU

A Mercury-free, flat light source which shows high luminance and luminous efficiency simultaneously has been developed. An electrodeless, dielectric barrier discharge is used to generate the plasma using Ne-Xe mixture gas of relatively low gas pressure of a few tens torr in a 4.1 inch diagonal size of flat panel. The basic properties of the long gap glow discharge and its accompanying instabilities, which prevents us from having high luminous efficiency discharge have been analyzed. A new structure and optimized driving methods have been used to generate a glow discharge which shows a wide voltage margin of a few hundred volts. The luminous efficiency and luminance could be 110 lm/W at $1300\;cd/m^2$ and 50 lm/W at $5500\;cd/m^2$.