Patent ID: 7176863

Claim:
An apparatus, comprising: a transmissive flat panel display having a matrix of liquid crystals, wherein said liquid crystals have a common node, said apparatus comprising analog common node voltage circuitry connected to said common node to establish a maximum rms voltage applied to said liquid crystals that falls along the lower knee of a transmittance vs. rms voltage curve that characterizes the performance of said liquid crystals, wherein said analog common node voltage circuitry provides an alternating pair of voltages to apply to said common node, wherein, said analog common node voltage circuitry comprises: a) a first circuit to provide a second alternating pair of voltages that, if applied to said common node, would provide for a larger rms voltage applied to said liquid crystals than provided for by said pair of alternating pair of voltages; b) a second circuit to reduce the peak-to-peak amplitude of said second alternating pair of voltages to produce said alternating pair of voltages.