TFT-LCD Drive Method and Driver LSI

Hiroyuki Mano, Systems Development Laboratory, Hitachi, Ltd.
Kazuhiro Ishida, Electron Tube & Devices Division, Hitachi, Ltd.
Satoru Tsunekawa, Semiconductor & Integrated Circuits Division, Hitachi, Ltd.


Liquid crystal displays addressed by thin-film transistors (TFT-LCDs) are used for displays in notebook-sized personal computers (PCs). In recent years, high-resolution, large screen TFT-LCDs have been used for LCD monitors, replacing the cathode-ray tube (CRT) displays of desktop PCs. The reasons TFT-LCDs are widely used for PC displays are their high quality, color capability, thinness and low power consumption. Hitachi has developed a low voltage, frame-rate control (FRC) drive method and a multi-color display-driver large-scale integration (LSI).

To realize a high-quality display with a low-voltage drive, we have reduced the resistance and capacitance of each electrode of the TFT-LCD. Using the low-voltage drive method, a 64-gradation, 256k-color data driver can be realized using a fine manufacturing process and integrated into a small-chip LSI. By using this 64-gradation driver LSI and the FRC drive method, the TFT-LCD can display a full 1670k colors. In addition, this paper describes how the drive method and data driver LSI will change in the future, accommodating higher resolutions and larger screen sizes.

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