投射式電容觸控面板之抑制雜訊處理及定位精準度改良

Noise Reduction and Accuracy Enhancement of Projected Capacitive Touch Panel Technology

張弘憲(Hung-Hsien Chang)

指導教授 ： 黃俊郎

共同指導教授 ： 陳中平(Chung-Ping Chen)

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2014年)

https://doi.org/10.6342/NTU.2014.00417

摘要

目前投射式觸控面板技術在計算觸控位置資訊時，容易有雜訊的問題，使得計算位置資訊時，其精準度及穩定度皆偏低。且現今的觸控面板的尺寸愈來愈大的情況下，雜訊所造成的影響便愈來愈嚴重。此外，由於不同的介質觸碰面板所產生的影響，會使量測出來的資訊產生反轉的現象，導致錯估位置資訊。螢幕邊緣的精準度也是目前觸控技術的一大難題，如何在欠缺邊緣資訊的情況下提昇邊緣的精準度。

因此在此篇論文中主要分成兩大部份：雜訊抑制以及精準度提昇。

在雜訊抑制的部份中，根據觸控面板的硬體架構進行討論，並從硬體架構的分析上找出其缺陷，利用將感應線分組處理的方式將無法由硬體去除的低頻雜訊改用後端演算法的方式加以抑制去除。

而在提昇精準度的章節中，根據重心法無法處理的情況如反轉現象及邊緣問題，此論文提出了一個新的方法投票法來修正重心法的缺陷。此外根據觸控面板邊緣的情況，此論文提出了延伸法及比較法等方式去嘗試解決重心法的不足。

最後，此篇論文為了提高測試環境的品質及速度，建立了一個由電腦數值控制機床為主的測試環境，利用此測試環境，提高測試品質及完成自動化測試的流程。

關鍵字

投射式觸控面板 ； 雜訊抑制 ； 精準度提昇 ； 投票法 ； 延伸法 ； 電腦數值控制機床

並列摘要

When we use the projected capacitive touch panel, the panel suffer from noise effect. The noise effect cause the inaccuracy and instability of the computed position. As the size of touch panel become larger and larger, the problem from noise become worse and worse. Besides, the coupling effect between human body and panel will cause inversion situation. The inversion situation will make the panel compute a wrong position. The accuracy on the border of the panel is another problem on the touch panel. We need to compute an accurate touch position without full information.

There are two parts in this thesis: noise reduction and accuracy enhancement.

According to the architecture of touch panel, low frequency noise effect cannot be removed completely. We proposed a new method to reduce the low frequency noise by dividing and grouping.

The original method to compute a touch position is the center-of-gravity method. However, inversion situation cannot select the main touch sensor correctly. We proposed a voting method to decide the main touch sensor. Besides, because of lacking information of touch sensors, we also proposed some methods such as extension method and comparison method to resolve the problem on the border case.

Last but not least, an automatic test environment was established by computer numerical control system. The test environment not only reduced the time of test but enhanced the accuracy during the operation.

並列關鍵字

Projected capacitive touch panel ； Noise reduction ； Accuracy enhancement ； Voting method ； Extension method ； Computer numerical control system

參考文獻

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