Energy-Saving Driver Design for Full-Color Large-Area LED Display Panel Systems

This paper demonstrates how the multilevel pulsewidth modulation (PWM) (MPWM) driving method can be implemented on a full-color large-area light-emitting diode (LED) display panel system through a low-cost modification of the existing hardware configuration. The method employs multiple LED driver modules connected in parallel which are combined to deliver MPWM current to individual LED pixels. For a three-level driving scheme, the criterion for selecting the midlevel current in order to maximize the luminous efficacy gain is derived mathematically. The algorithm for video signal conversion required for deriving the subvideo signals from the original high-definition multimedia interface or digital visual interface video signal for activating multiple LED driver modules is also discussed.