Abstract: The number of external column driver chip can be reduced to one in an active matrix liquid crystal display with column input multiplexing driving scheme. At least two sample and hold circuits are used for each column with alternate sampling and holding periods. Video signals are sampled and held at least twice during one line scanning time. These sample and hold circuits are all integrated in the driver chip.

Abstract: A redundant row select driver circuit system is provided for enhancing manufacturing yield and reducing manufacturing costs in the liquid crystal data displays. In particular, a row select driver circuit is provided with redundant subcircuits that can effectively replace any damaged subcircuit within the row select driver circuit. In addition, there is disclosed a capacitance compensating scheme to adjust the gray scale level in a damaged row select line with a break inside the display area. And finally, an enhanced diagnostic scheme is disclosed for testing of each row select driver subcircuits in a active matrix display having row select driver circuits connected to each end of row select lines.

Abstract: An LCD display having at least one redundant data driving circuit on a substrate that can be substituted for a defective data driving circuit on the substrate. These redundant subcircuits are exact copies of a column driving subcircuit except that some of the connecting points to the control and driving signal lines are not hardwired. That is, the connecting points are left as potential welding points. If a column driving circuit that is coupled to a particular input data line is damaged, then a redundant data driving subcircuit can be hardwired by welding the corresponding crossing points to compensate the damaged circuit. The damaged circuit is also disconnected (by using a laser cut or compatible methods) from the corresponding input data line and the internal data line as necessary.