Energy efficient LED driving system for large-scale Video display panel

This paper shows how an energy efficient LED driving system can be implemented on a full-color large-scale Video display panel through a low-cost modification of conventional hardware configuration. The proposed system employs multiple LED driver modules connected in parallel that are combined to deliver multi-level PWM current to individual LED pixels. The implementation of the proposed driver is illustrated with a three-level driving scheme. The criteria for selecting current levels in order to maximize the luminous efficacy gain is derived mathematically. The algorithm for video signal conversion that requires for deriving sub-video signals from the original HDMI or DVI signal to activate multiple LED driver modules is also discussed. Experimental results show an average gain of 15% on luminous efficacy over the ON-OFF PWM driving scheme by the proposed method.