A display device uses a light emitting device with heightened luminance at an outermost area thereof as a light source to enhance luminance uniformity of a display panel. In one embodiment, an RF power converter includes an RF switching converter, a low-drop out regulation circuit, and an RF filter. In one aspect, a solid support is provided that includes a plurality of single-stranded oligonucleotides immobilized thereon by a linker cleavable under conditions of matrix-assisted laser desorptionionization mass spectrometry; and matrix for performing MALDI mass spectrometry, wherein the support comprises a flat surface. The battery bank receives multiple charging currents from multiple power sources, such as a grid power source and an auxiliary power source.