Design and Simulation of the Pixel Circuit for a 6-in Full HD LTPS TFT LCD Based on the New Digital Driving Method

• Published in: Journal of display technology 2015-04, Vol.11 (4), p.336-340
• Main Authors: Tai, Ya-Hsiang, Chang, Chun-Yi, Lin, Chun-Yu
• Format: Article
• Language: English
• Subjects: Capacitance; Data driver; digital; Discharges (electric); Educational institutions; liquid crystal displays (LCDs); Logic gates; low-temperature polycrystalline silicon TFT (LTPS TFTs); Power demand; Resistance; Thin film transistors
• ISSN: 1551-319X; 1558-9323
• DOI: 10.1109/JDT.2015.2389235

For all of the electronic modules in a liquid crystal display (LCD), the power consumption of data driver is only second to the backlight. Most of the power is used for converting the signal from digital to analog. In this paper, we proposed a new kind of pixel circuit with fully digital driving. As a result, the signal converting part in the conventional data driver can be omitted, and thus the power consumption can be greatly reduced. The proposed pixel circuit contains two thin-film transistors (TFTs) and a resistor in series, forming a discharging path for pixel voltage. There is also another transistor used to preset the pixel voltage. The gray level is controlled by the pulse width of the data source when the pixel is enabled by the scan voltage. The operation of the novel design is verified by simulation in the cases of a full high-definition panel. The proposed pixel circuit with the new driving method is an innovation approach to reduce data driver power consumption.