應用於非晶矽薄膜電晶體液晶顯示器內嵌式觸控電路與閘極驅動電路之研究

Abstract

在現今的科技生活中，人們對於顯示器的品質需求越來越多，無論是畫面品質或是產品外觀。因此System-on-panel的技術已成為發展的重點，此技術不但可節省製造成本與提高良率並且具有縮減產品模組、實現高可靠度與高解析度顯示器等特性。 在此篇論文中，提出兩種應用於顯示器的電路，第一個為整合型的雙向閘極驅動電路，其利用了四組驅動訊號實現單一路徑充放電的功能與減少元件的劣化並且可得到低功率消耗的優點。此閘極驅動電路已成功驗證於4.5吋面板上並通過手機規格的信賴性試驗。 第二個為內嵌式觸控電路，其包含畫素內混和式感測器與讀出電路的設計。此感測器利用結合液晶電容與光感測的方式提高感測極限。此外，為了驗證混和式感測器對於觸碰與否的感測，在玻璃基板上實現一使用非晶矽電晶體製作的類比數位轉換器(ADC) ，將觸碰產生的類比訊號轉換為數位訊號，而此ADC最小可分辨電壓差為1V。

It is popular and inevitable for us to have many instruments with display screens in our life. The requirements of qualities whatever in image or appearance of apparatus have become more sophisticated. A revolutionary technology of TFT LCDs has been developed quickly which is system-on-panel (SOP) applications. However, SOP application has the potential to realize compact, highly reliable, and high resolution display by integrating functional circuits within a display. Besides, the cost of panel becomes lower, as well as the higher yield rate can be achieved. In this thesis, we proposed two main circuitries for TFT LCDs; the first one is a bi-directional gate driver. It has been designed and fabricated by amorphous silicon (a-Si) technology. With utilizing four clock signals in the design of gate driver on array (GOA), the pull-up transistor has ability for output charging and discharging. Moreover, lower duty cycle of clock signals can decrease static power loss to further reduce the overall power consumption and suppress the degradation of devices. The proposed gate driver has been successfully demonstrated in a 4.5-inch (1620xRGBx960) TFT-LCD panel and passed reliability tests of the cell phone standard. The second is an in-cell touch circuit which includes hybrid-type touch sensors and readout circuits. This hybrid-type touch sensor enables wide sensing range owing to integrated with liquid-crystal capacitive and optical sensors. Furthermore, an on-glass readout circuit for hybrid-type touch sensors is verified. The switched-capacitor (SC) technique is applied to eliminate the voltage variation from the operation time and manufacture process for analog-to-digital converter (ADC). The minimum detectable voltage difference of the ADC is 1V. By applying the analog-to-digital converter, the touched and untouched events can be converted to the digital output.