三維顯示模式之主動式矩陣有機發光二極體顯示器之畫素電路必須提高畫面的更新頻率使其能在16.6 ms 內將畫面分別呈現於左右眼，藉此產生視覺深度感。由於畫素電路採用薄膜電晶體作為驅動與開關元件，其臨界電壓與電子漂移率會產生製程上的誤差或因長時間的操作造成漂移，導致驅動面板的電流均勻性下降。此外，有機發光二極體材料會隨著長時間的使用而老化，造成整體面板的亮度與均勻性下降，進而對於畫面品質造成影響。現今二維顯示器中已經有許多相關畫素補償電路被提出來改善上述的缺失，但是對於高解析度或高操作頻率的三維顯示器而言，能否在受限制的補償時間內解決上述之所有缺陷，已經成為一個重要的議題。
本論文針對上述問題提出三個新式畫素補償電路。第一個電路採用同步式驅動法以適用於高操作頻率之三維顯示器，其利用5T2C的電路架構來補償低溫多晶矽薄膜電晶體臨界電壓的變異，在有機發光二極體因材料老化時，所提出的電路也可以提供額外的電流來維持亮度穩定性，此外，此畫素電路之驅動電流也不受寄生電阻所造成之電壓源壓降與薄膜電晶體之寄生電容所影響。從模擬結果可知，電路成功補償了薄膜電晶體臨界電壓的變異，且在不同薄膜電晶體寄生電容與不同灰階之下，其電流誤差率皆在1% 以內，而當有機發光二極體材料老化時，所提出的電路也能有效的維持亮度穩定性。然而，此電路採用之低溫多晶矽薄膜電晶體有著高成本與高製造溫度之缺點，因此提出第二個6T2C電路將非晶相銦鎵鋅氧化物薄膜電晶體應用在畫素電路上，在增加一個元件的條件之下使電路適用於非晶相銦鎵鋅氧化物薄膜電晶體，並且保留第一個電路補償薄膜電晶體之臨界電壓變異與有機發光二極體之材料老化的功能。利用實際量測之非晶相銦鎵鋅氧化物薄膜電晶體的特性來建立模擬所使用的參數，且由模擬結果可知，在有機發光二極體之臨界電壓漂移0.5 V時依然可以保持亮度穩定性，所以本電路可以補償薄膜電晶體臨界電壓的變異並且增加顯示器的顯像壽命。然而由於第二個電路使用過多的畫素元件，導致訊號線複雜及開口率下降，因此第三個電路即使用4T2C的架構來補償電晶體臨界電壓值與電子漂移率的變異和有機發光二極體亮度的衰減，並且採用平行補償使此電路適用於高解析度顯示器。實際量測另外的非晶相銦鎵鋅氧化物薄膜電晶體的特性來建立一組模擬所使用的參數，由模擬可知在薄膜電晶體臨界電壓漂移1 V 或電子漂移率漂移 20% 之下，電流誤差率皆小於4%，並且在有機發光二極體材料老化至臨界電壓漂移0.9V時，亮度之變異也在4% 之內，因此本電路可以補償薄膜電晶體臨界電壓與電子漂移率之漂移，並且提高顯示器之解析度與顯像壽命。本論文所提出的三個電路皆能成功地減少由薄膜電晶體與有機發光二極體之老化所造成之亮度不均勻或下降之現象，因此，這些電路對於顯示器之應用有著顯著之貢獻。

For three-dimensional (3D) active matrix organic light emitting diode (AMOLED) displays, the display frame rate should be increased to send images to the left and right eyes within 16.6 ms for producing depth perception. Since the pixel circuit adopts thin film transistors (TFTs) as the driving and switching components, the VTH and mobility of TFTs vary due to process variation and long-term operation, leading to the decrease of current uniformity of the panel. Moreover, the OLED material degrades under long-term operation which causes drops in luminance and uniformity of the panel, hence influencing the image quality of the display. Several compensating pixel circuits have been proposed to improve the shortcomings of two-dimensional (2D) AMOLED displays. However, for high-resolution or high-speed operation three-dimensional (3D) AMOLED displays, the capability to solve all the aforementioned problems within the limited programming time has become an important issue.
This thesis proposes three new compensating pixel circuits which address the aforementioned problems. The first circuit adopts a simultaneous emission (SE) driving scheme to be suitable for use in 3D displays. The circuit utilizes a 5T2C structure to compensate for the VTH variations of low temperature poly-silicon (LTPS) TFTs, and additional current is provided to maintain luminance stability as the OLED degrades. Moreover, the driving current of the pixel circuit will not be influenced by current-resistance supply voltage drops and TFT parasitic capacitances. Based on simulation results, the circuit successfully compensates for the VTH variation of TFT, while the current error rates all fall below 1% as different parasitic capacitances of TFTs and different gray levels are provided. Furthermore, the circuit can effectively maintain luminance stability as the OLED degrades. However, this circuit adopts LTPS TFT which has the drawbacks of high cost and high processing temperature. Thus, the second 6T2C circuit is proposed to apply amorphous indium gallium zinc oxide (a-IGZO) TFTs to the pixel circuit. In conditions necessitating use of one additional component, the circuit can be suitable for a-IGZO TFTs and retain the compensating functions with regards to VTH variations of TFTs and OLED degradations in the first pixel circuit. The electrical characteristics of a-IGZO TFTs are measured to establish a simulation model. According to simulation results, the normalized luminance of OLED maintains stability, while the OLED shifts by 0.5 V. Consequently, this circuit can compensate for the VTH shifts of TFTs and increase the lifetime of displays. Due to the fact that the second circuit uses an excessive number of elements, it results in complex control lines and a low aperture ratio. Therefore, the third proposed circuit uses the 4T2C structure to compensate for the mobility and VTH shifts of TFTs, while the OLED luminance drops and adopts the parallel addressing method in order to render the circuit suitable for high-resolution displays. The simulation model is established through measuring the electrical characteristics of another a-IGZO TFT. Based on simulation results, current error rates all fall below 4%, as the shift of TFT VTH is 1 V or the shift of TFT mobility is 20%. Moreover, when the OLED material degrades and the VTH of OLED shifts by 0.9 V, current error rates also fall below 4%. Hence, the proposed circuit can compensate for the VTH and mobility shifts of TFTs, increasing the resolution and lifetime of displays. The proposed three circuits successfully reduce the non-uniformity and luminance decay caused by the degradation of TFTs and OLEDs. Consequently, these circuits make a significant contribution to the applications of AMOLED displays.

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