38.2: The Electro-Optic Characteristics of MFFL (Mercury-Free Flat Fluorescent Lamp) for LCD Backlighting

In this work, we have studied the electro‐optic characteristics of multi‐cell structured, highly efficient Mercury‐free Flat Fluorescent Lamp (MFFL). It was found that each cell of the newly suggested multi‐cell structured MFFL could be operated independently by the pulse amplitude modulation, and/or pulse width and/or frequency modulation method which can be utilized to make a back light source for LCD with an areal dimming capability. A wide driving voltage margin of stable glow enabled to have a large luminance variation which resulted in the dimming ratio of 14%, while the frequency and the pulse width modulation resulted in the dimming ratio of 25 and 31% respectively. The interconnection of multi‐cell structured MFFL for the full size LCD together with its driving wave form for the independent operation of each cell with a 4 bit sub‐field method and its consequent 16 level lighting for each TV field are suggested.