由於出色的色彩表現、快速的響應時間、高對比度和低功耗等優點，主動式有機發光二極體（AMOLED）廣泛應用於顯示技術。近年來，高階攜帶式產品的顯示面板不僅要求高解析度 (high resolution)和高密度顯示圖像 (pixels per inch, PPI)，而且還提供低功耗。此外，具有可調式畫面更新率 (adjustable frame rates)的攜帶式產品為現今最尖端的技術。高畫面更新率 (High frame rate, HFR) 技術用於遊戲或觀看電影等高動態之應用中實現卓越的畫面表現。相反的，低畫面更新適用於智能手錶等節能應用。
在第三章中，我們提出一個全新的 6T1C LTPO AMOLED 畫素電路，其能夠應用於1 到 120 Hz 的可調式畫面更新率的攜帶式顯示器。為了精簡電路結構中的控制信號線(control signal lines)和電晶體的數量以達到高密度顯示圖像，操作時脈設計中加入了穩定區間(holding period)。且此電路能夠免疫於OLED的VTH變異，能夠補償OLED的老化問題。總結來說，於第三章提出之電路具有 5 V 的低壓驅動；操作於高畫面更新率120 Hz時，且驅動電晶體的臨界電壓變異量為±0.33 V，平均誤差率(error rate)為1.8%。此外畫素電路工作在低畫面更新率1 Hz時，OLED驅動電流的變變異最大僅3.56nA，在高低畫面更新率運作皆表現出極高的穩定度。
在第四章中，我們提出了新穎的 6T1C LTPO 畫素電路，可以同時補償臨界電壓和載子遷移率(Mobility)的變異，主要應用於4K（3840 × 2160，UHD）攜帶式裝置。電路中的遷移率補償方法使用兩種不同的補償機制，成功地降低遷移率變異的影響。為了提高顯示畫面品質，在提高解析度和顯示畫面密度的同時，簡化了電路架構複雜度。且電路對IR-drop和OLED的VTH變異的免疫能力將有利於呈現均勻的圖像。總結來說，於第四章提出之電路可以在5V低壓驅動下產生高度均勻和穩定的 OLED電流，在±0.33 V臨界電壓變異且±30%遷移率變異的條件下，OLED電流的最大誤差率分別為4.25%和0.013%。因此，所提出的6T1C畫素電路非常適合用於可攜式的AMOLED顯示器。

Because of the benefits of outstanding color characteristics, short response time, high contrast ratio, and low power dissipation, active-matrix organic light-emitting diodes (AMOLED) have been widely used in display technologies. Recently, the trend of the display panels of high-end portable devices not only requires high resolution and pixels per inch (PPI) but also provides low power consumption.
In the chapter 3, we proposed a novel 6T1C pixel circuit with an LTPO structure for portable displays with variable frame rates ranging from 1 to 120 Hz. To reduce the number of control signal lines and TFTs in the proposed circuit structure, a holding period is used. In addition, the proposed circuit is independent of the variations of VTH of OLED that provides the immunity to the OLED-degenerated issues. The proposed circuit is provided with low-voltage driving of 5 V, operating at 120 Hz with average error rates of 1.8% of OLED currents while the DTFT’s VTH variations are ±0.33 V. Furthermore, although the proposed pixel circuit operates at 1 Hz, the overall variations in OLED driving currents are less than 3.56nA.
In the chapter 4, we proposed a novel 6T1C LTPO pixel circuit that can compensate for both the threshold voltage and field-effect mobility variations, being mainly used in 4K (3840 × 2160, UHD) portable displays. The mobility compensating process of the proposed circuit is based on two different mechanisms that successfully minimize the influence of field-effect mobility variations. In order to improve the image quality, while increasing the screen resolution and PPI, the number of control signal lines and TFTs in the proposed circuit are simplified. The immunity of both IR-drop issues and the variations in VTH of OLED (VTH_OLED) are favorable for presenting a uniform image. The proposed pixel circuit can produce a highly uniform and stable OLED current with 5V low-voltage drive, operating with maximum error rates of 4.25% and 0.013% for OLED currents under the condition of VTH variations at ±0.33 V with mobility variations at ±30 %, respectively. As a result, the proposed 6T1C pixel circuit is a good candidate for use in portable AMOLED displays.

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