An SXGA reflective liquid crystal projection light valve incorporating inversion by pixel bootstrapping

A new experimental SXGA liquid-crystalon-silicon reflective projection light valve is described. It incorporates a novel inversion scheme, the bootstrapped pixel method, which extends the available pixel voltage range with lower applied voltages from the external data driver. This can enable the use of liquid crystal modes and performance-enhancing pixel structures which increase the pixel voltage requirement without incurring the additional cost of higher-voltage technology in the lightvalve chip or the data driver. Alternatively, with present liquid crystal modes and pixel structures, it can permit the use of a denser, lower-voltage silicon process permitting more function on a chip or smaller, less expensive chips. Using the new light valve, the pixels were operated at 12 V peak-to-peak, the technology maximum, with no voltages in the device above 12 V and a data-line voltage range of 6 V. The new method introduces no new image artifacts.