A novel LCD backligth with mixed white and colorful LEDs

With improved luminous efficiency, reduced cost, long lifetime, wide color gamut, fast response, LEDs are becoming a suitable solution for LCD backlight. Backlight consisting of white LEDs has the merit of high luminous efficiency while is not possible to change color temperature. Backlight with colorful LEDs of red, green, blue to form white lights can reach various color temperatures while luminous efficiency is not as high as white LED backlight. A mixed backlight combining white and colorful LEDs is presented in this paper to preserve the merits of both kinds of LED backlights. High luminous efficiency white LEDs provide most of luminance and colorful LEDs are only lightened when color temperature is to change. An implementation is realized. The experimental results show that the theoretical model is appropriated and the mixed backlight presents the high luminous efficiency with less LEDs and possibility to change color temperature.