ScanVue Technologies provides licensing and technical support on innovative AMLCD technology, including its proprietary low cost Dual Select Diode (DSD) flat panel display technology. Services cover licensing, consulting on proven DSD matrix array processes, CVD process recipes for diode fabrication, circuit modelling, design and layout of DSD active matrix arrays, selection of drive methods and driver ICs and seminars and tutorials on DSD LCDs.
DSD Technology
In Active Matrix LCDs each LC pixel in the array must be accurately charged to the data voltage, which is then sustained during the frame time. Instead of using a conventional Thin Film Transistor (TFT) for this purpose, the DSD AMLCD uses at each pixel a precision voltage divider with two equal nonlinear resistors or Thin Film Diodes. The pixel charges accurately to the data voltage even when the nonlinear resistors change signifcantly over time or across the display area. The result is excellent display image quality with uniform gray shades and without image retention.
The manufacturing process for DSD LCDs is much simpler than for TFT LCDs. While a TFT matrix requires four to six photomask steps, the DSD matrix needs only two or three photomask steps and also requires fewer and shorter deposition and etch steps. The DSD LCD can be scaled up to sizes larger than 40 inch with relaxed design rules and a better manufacturing yield than TFT LCDs.
DSD AMLCDs have been demonstrated in 2 to 14 inch color displays. The photograph at the right shows a 10.4 inch color VGA display. DSD AMLCDs have great potential to significantly reduce the cost of displays for many applications, while maintaining the same image quality as TFT LCDs. The type of equipment used in a DSD array line is not different from a TFT array line. The number of tools for the same output is, however, significantly reduced.
Publications
DSD AMLCD technology has been presented at international conferences and in scientific journals:
