标题: | 具有温度补偿功能之非晶矽薄膜电晶体闸极驱动阵列电路技术研究 Study on the integration of temperature compensation and gate driving circuits based on amorphous silicon TFT array technology |
作者: | 郭奕君 Kuo, Yi-Chun 刘柏村 Liu, Po-Tsun 显示科技研究所 |
关键字: | 液晶显示器;系统面板;薄膜电晶体;LCD;System-On-Panel;TFT |
公开日期: | 2011 |
摘要: | 薄膜电晶体液晶显示器(thin-film transistor liquid-crystal display,简称TFT-LCD)为现代显示科技产品的主流,尤其应用于手机上,有轻巧、方便携带等特点。传统的液晶显示器显示正确影像的方式是利用外部的驱动晶片来提供面板所需要的驱动电压,近年来为了要达到轻巧、薄型化与降低生产成本的目标,系统整合式玻璃面板(SOG, System-on-glass)的概念陆续被提出,许多产品将面板周边的电路直接制作在玻璃基板上,如闸极扫描驱动电路整合于液晶面板(gate driver on array, GOA)之技术。然而,TFT-LCD之画素利用非晶矽薄膜电晶体(amorphous Silicon TFTs, 简称a-Si TFTs)作为开关,来控制显示的画面,而非晶矽薄膜电晶体之特性容易受温度影响,其闸极在相同电压下,温度愈高,流经汲极与源极的电流愈大;相反的,温度愈低,流经汲极与源极的电流愈小,所以温度容易影响到显示画面的特性如对比度、Gamma曲线等。因此,如何使液晶显示面板在不同的环境温度下仍能具有良好的画面品质,是很重要的课题。 在本篇论文中,提出一个玻璃基板上的温度补偿电路设计,此电路包含温度感测器、多工器、电位移转器电路并与GOA技术整合,藉由非晶矽薄膜电晶体之温度特性设计出的温度感测器能侦测环境温度变化,进而推动GOA,使GOA输出之闸极讯号可根据温度变化而改变电位,即可以调整后的闸极讯号控制画素之电晶体。此电路均以非晶矽薄膜电晶体作为电路的驱动元件,可实现显示器周边电路整合的应用。 Thin-film transistor liquid-crystal display (TFT-LCD) becomes a main stream for display technology in this generation. It features light weight, fine portability, especially for cellular phones. Traditional LCDs display the correct images by using external IC chips which provide the required driving voltage of panels. In recent years, the concept of system-on-glass panels is proposed progressively in order to achieve the goals of compact, thin and low cost displays. Many products integrate the peripheral circuits on the glass substrate such as the gate driver on array (GOA) technology. However, the pixels of TFT-LCD use amorphous Silicon TFTs (a-Si TFTs) as switch devices to control the images. The ambient temperature influences the electrical characteristics of a-Si TFTs. As the temperature increases, the TFTs turn on at a lower gate-source bias and the corresponding drain-source current level increases. On the contrary, as the temperature decreases, the TFTs turn on at a higher gate-source bias and the corresponding drain-source current level decreases. Therefore, the temperature influences the characteristics of the LCD panel, including the contrast ratio and gamma curve. The important subject is how to make the LCD panels with good image quality under various ambient temperatures. In this thesis, the integration of on-glass temperature compensation circuit and GOA technology is proposed. The temperature compensation circuit comprises the temperature sensor, multiplexer and level shifter circuits. It detects the ambient temperature changes by the temperature sensor circuit which is designed based on the temperature characteristics of the a-Si TFTs and drives GOA. Then, GOA generates the gate pulse signals with the modulated levels associated with the temperature. In this way, the pixels can be controlled by the modulated gate pulse signals. The circuits directly use a-Si TFTs as the driving devices; and further, SOG application can be implemented. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT079915508 http://hdl.handle.net/11536/49525 |
显示于类别: | Thesis |