Data driver architecture and driving scheme of AMOLED microdisplay for mobile projectors

For a mobile projector application that can be embedded in a cellular phone, a 6-bit data driver integrated in a 0.4-inch diagonal VGA AMOLED on silicon substrate is proposed. The proposed data driver has a couple of features tailored for a microdisplay application: To be integrated with a very fine pixel pitch of 4.2 ¿m, the data driver uses a 33-degree demultiplexing scheme, thereby taking circuit area within the peripheral height of 810 ¿m. In addition, the separate gamma correction is provided to resolve the color shift problem due to the transmittance mismatch of red, green, and blue color filters. In spite of the separate gamma correction involved, the height of the data driver is not increased, because it is realized by making use of a time sharing method synchronized with the 33-degree demultiplexing.