應用於內嵌式有機發光二極體電容式觸控面板 之感測電路及系統

Abstract

本論文目的為In-cell電容式觸控面板感測系統包括感測電路及電極設計及畫面顯示。本論文的觸控面板為內嵌式架構，在厚度與成本上具有優勢，但也因此讓靈敏度降低與雜訊影響等影響因素。利用有限元素模擬軟體分析in-cell 觸控面板特性進而設計出最佳有效電極。電路上使用切換式電路技術的應用有助於提高電壓差異與減少功率消耗，而修正的二次取樣技術則是應用於消除來消除手指的低頻雜訊與利用外加電壓防止輸出飽和提高觸控面板之解析度。採用12-bit的類比數位轉換器去識別不同的觸控位置條件，主動式有機發光二極體讀取電路的數位部分可以採取校正演算法消除面板的背景基值。而動態平均的演算法則提供了可調式的訊雜比功能以及報點率去提高對雜訊的容忍度以及觸控解析度。而被動式的周邊電極則是使用多項式插值法計算出觸控位置。利用DAQ傳送數位訊號顯示觸控反應。主動式矩陣觸控面板的讀取電路達到52 dB的訊雜比以及200 Hz的報點率在0.88英吋的面板上。被動式有機發光二極體的讀取電路則為41 dB的訊雜比以及100 Hz的報點率在1.6英吋的面板上。

The purpose of this paper is to design the sensing system include readout circuit and electrode of In-cell capacitive touch panel. The touch panel of this paper is an embedded architecture, which has advantages in thickness and cost, but also causes the influence of sensitivity and noise. Using the finite element simulation software to analyze the in-cell touch panel characteristics and then design the best effective electrode. The switched-capacitor technique is applied to enlarge the voltage difference from capacitance changes of the touch panel and reduce power consumption, while the modified corrected double sampling (CDS) is used to eliminate the low frequency noise to eliminate the finger and using add-voltage to prevent the output saturation. The resolution of the touch panel uses a 12-bit analog-to-digital converter to identify different touch position conditions. The digital part of the active organic light-emitting diode reading circuit can take a correction algorithm to eliminate the baseline of the panel. And the algorithm of moving average provides a reconfigurable SNR and reporting rate with high noise immunity and touch sensitivity. The passive peripheral electrode uses polynomial interpolation method to calculate the touch position. Use DAQ to transmit digital signals to display touch reactions. The SNR of active-matrix touch panel read circuit achieves 52 dB and a 200 Hz reporting rate on a 0.88-inch panel. The SNR of PMOED read circuit achieves 41 dB and a 100 Hz reporting rate on a 1.6-inch panel.