氫化非晶矽薄膜電晶體的製造技術純熟、成本較低、具有均勻的元件特性與在可見光波長中有良好的感光度，因此被廣泛的應用於顯示器驅動電路與光感測器電路中。相較於外掛式觸控技術，內嵌式觸控技術具有較輕薄的架構、較高的亮度與較低的製造成本，其中內嵌式觸控又可分為電容式偵測與光學式偵測，然而就電容式偵測方面，分時驅動法會造成氫化非晶矽閘極驅動電路因為長時間的閘-源極偏壓操作而產生臨界電壓的漂移，縮短電路的使用壽命；光學式偵測方面，由於氫化非晶矽光感測電路在可見光波長中容易受到環境光之影響以及光感測電晶體長時間汲-源極偏壓等問題，降低了光感測電路之偵測準確度與可靠度。
針對上述之問題，本論文提出一個適用於內嵌式觸控之非晶矽閘極驅動電路與三個適用於互動式裝置之光感測電路，並經由電路模擬軟體或實際量測結果證明所提出電路之可行性。第一個電路為一適用於分時驅動法之非晶矽閘極驅動電路。為了避免在觸控感測階段因長時間偏壓影響造成驅動薄膜電晶體之臨界電壓漂移，此電路會先將Q點放電再利用預充電架構產生的微小電流，對Q點緩慢充電至高電位，藉此降低偏壓對驅動薄膜電晶體老化之影響。根據模擬結果，此電路之輸出波形在觸控感測前之上升與下降時間分別為3.29 μs與1.87 μs，觸控感測後之上升與下降時間分別為3.35 μs與1.89 μs，上升與下降時間誤差比率分別為1.82%與1.07%，證明電路在觸控感測前後均可以維持相似的上升時間與下降時間，因此所提出之閘極驅動電路可應用於內嵌式觸控架構之薄膜電晶體液晶顯示器。第二個電路為一4T1C之非晶矽光感測電路，針對量測結果去比較在不同環境光強度照射下之不同顏色(紅色R、綠色G、藍色B)的光感測電晶體所產生之光電流大小，進而得到較合適光感測電晶體之尺寸大小，以達到較高之訊雜比與不同顏色之間均有良好的感測能力，確保光感測電路之高準確度與高穩定性。根據量測結果可得知當藍光、紅光與綠光分別做為主要感測光源，其尺寸大小均為60 μm / 8 μm時，補償薄膜電晶體的尺寸大小分別應為30 μm / 8 μm、15 μm / 8 μm與介於60 μm / 8 μm ~ 120 μm / 8 μm之間，當有感測光源輸入時，所得到之輸出電壓分別為12.85 V、12.4 V與13.19 V，均為一相對高之電壓值，藉此驗證出各個不同顏色光源輸入時，主要感測光感測電晶體與補償電晶體間較合適之尺寸比率。由於非晶矽薄膜電晶體元件會因為長時間高偏壓產生臨界電壓漂移現象，進而影響到電路的穩定度與使用壽命。因此，第三個與第四個電路各提出一提升電路穩定度與增加電路可應用輸入顏色光源之非晶矽光感測電路，所提出之光感測電路利用對稱的架構交替操作去感測主要的輸入顏色光源 (RGB)，達到降低光感測電晶體之臨界電壓漂移現象。此外，所提出之對稱架構交替操作也可以應用於感測混色光源輸入 (R+RB)，利用交替感測主色 (RGB)與混色 (RG、GB與BR)光源輸入，使光感測電路由感測三個顏色之光源增加至六個顏色之輸入光源，提升光感測電路之更多顏色光源之應用，使互動式電子白板可感測更多顏色之輸入光源。

SUMMARY

This thesis presents four circuits based on hydrogenated amorphous silicon (a-Si:H) technology which apply to TFT-LCDs, including one gate driver circuit with in-cell touch structure and three optical sensor circuits. For use in the in-cell touch panel, the proposed a-Si:H gate driver circuit with time-division driving method (TDDM) can reduce threshold voltage shift of driving TFT. To achieve a high SNR and similar sensing results from each optical pixel sensor, photo TFTs with different channel widths are fabricated and utilized to realize an optimized optical sensor circuit structure. Moreover, two a-Si:H optical sensor circuits utilize the ac-driving method to suppress the threshold voltage (VTH) shift of main photo TFT. Based on the simulation and measurement results, the proposed a-Si:H gate driver circuit can successfully generate output waveforms with in-cell touch sensing, and three a-Si:H optical sensor circuits achieve a high SNR with different optical input signal of three primary colors.

Keywords: Amorphous silicon thin-film transistor, gate driver circuit, in-cell, interactive panel, optical sensor circuit.

[1] U. B. Kang and Y. H. Kim, “A new COG technique using low temperature solder bumps for LCD driver IC packaging applications,” IEEE Trans. Compon. Packag. Technol., vol. 27, no. 2, pp. 253-258, Jan. 2004.
[2] H. Kristiansen and J. Liu, “Overview of conductive adhesive interconnection technologies for LCDs,” IEEE Trans. Comp., Packag., Manuf. Technol. A, vol. 21, no. 2, pp. 208-214, Jan. 1998.
[3] Y. H. Tai, “Design and operation of TFT-LCD panels,” Wunan, 2006.
[4] R. Joshi, “Chip on glass-interconnect for row/column driver packaging,” Microelectr. J., vol. 29, pp. 343-349, Jun. 1998.
[5] J. Liu, “ACA bonding technology for low cost electronics packaging applications current status and remaining challenges,” in Proc. 4th Int.Conf. Adhesive Joining and Coating Technology Electronic Manufacturing, pp. 1-15, 2000.
[6] C. T. Liu, “Revolution of the TFT LCD technology,” J. Display Technol., vol. 3, no. 4, pp. 342-350, Dec. 2007.
[7] J. C. Hwang, “Advanced low-cost bare-DIE packaging technology for liquid crystal displays,” IEEE Trans. Comp., Packag., Manuf. Technol., A, vol. 18, no. 3, pp. 458-461, Mar. 1995.
[8] S. H. Lo, C. C. Wei, W. C. Lin, I. Wang, C. C. Shih, and Y. E. Wu, “Integrated gate driver circuit with one conduction path for charge-discharge,” in SID Symp. Dig., 2006, pp. 231-234.
[9] S. H. Moon, Y. S. Lee, M. C. Lee, B. H. Berkeley, N. D. Kim, and S. S. Kim, “Integrated a-Si:H TFT gate driver circuits on large area TFT-LCDs,” in SID Symp. Dig., 2007, pp. 1478-1481.
[10] C. Hordequin, J. M. Bayot, T. Kretz, S. Yon, S. Arfuso, N.Szydlo, and H. Lebrun, “A 1” VGA LC light valve using a-Si:H TFTs with integrated drivers,” EuroDisplay 02, pp. 387-390, 2002.
[11] J. H. Yang, S. C. Jung, Y. S. Son, S. T. Ryu, and G. H. Cho, “A noise-immune high-speed readout circuit for in-cell touch screen panels,” IEEE Trans.Circuits Syst. I, Reg. Papers, vol. 60, no. 7, pp. 1800-1809, Jul. 2013.
[12] Y. Teranishi, K. Noguchi, H. Mizuhashi, K. Ishizaki, H. Kurasawa, and Y. Nakajima, “New in-cell capacitive touch panel technology with low resistance material sensor and new driving method for narrow dead band display,” in SID Symp. Dig., 2016, pp. 502-505.
[13] C. H. Chiang, Y. E. Wu, K. T. Ho, and P. Y. Chan, “Mutual-capacitance in-cell touch panel,” in SID Symp. Dig., 2016, pp. 498-501.
[14] W. den Boer, A. Abileah, P. Green, T. Larsson, S. Robinson, and T. Nguyen, “Active matrix LCD with integrated optical touch screen,” in SID Symp. Dig. Tech. Papers, May 2003, vol. 34, no. 1, pp. 1494-1497.
[15] G. Kawachi, M. Ishii, and N. Konishi, “Transient behavior of the a-Si:H/Si3N4 MIS capacitor and its impact on image quality of AMLCDs addressed by a-Si:H thin-film transistors,” J. Display Technol., vol. 3, no. 1, pp. 52-56, Mar. 2007.
[16] Y. S. Son and G. H. Cho, “Design considerations of channel buffer amplifiers for low-power area-efficient column drivers in active-matrix LCDs,” IEEE Trans. Consumer Electronics, vol. 54, no. 2, pp. 648-656, May 2008.
[17] J. S. Chen and M. D. Ker, “New gate-bias voltage-generating technique with threshold-voltage compensation for on-glass analog circuits in LTPS process,” J. Display Technol., vol. 3, no. 3, pp. 309-314, Sep. 2007.
[18] C. L. Lin, C. C. Hung, W. Y. Chang, K. W. Chou, and C. Y. Chuang, “New a-Si:H AMOLED pixel circuit to ameliorate OLED luminance degradation by external detection,” IEEE Electron Device Lett., vol. 32, no. 12, pp. 1716-1718, Dec. 2011.
[19] C. L. Lin, F. H. Chen, C. C. Hung, P. S. Chen, M. Y. Deng, C. M. Lu, and T. H. Huang, “New a-IGZO pixel circuit composed of three transistors and one capacitor for use in high-speed-scan AMOLED displays,” J. Display Technol., vol. 11, no. 12, pp. 1031-1034, Dec. 2015.
[20] C. L. Fan, Y. C. Chen, C. C. Yang, Y. K. Tsai, and B. R. Huang, “Novel LTPS-TFT circuit with OLED luminance aompensation for 3D AMOLED displays,” J. Display Technol., vol. 12, no. 5, pp. 425-428, May 2016.
[21] C. L. Lin, M. H. Cheng, C. D. Tu, and M. C. Chuang, “Highly reliable integrated gate driver circuit for large TFT-LCD applications, ” IEEE Electron Device Lett., vol. 33, no. 5, pp. 679-681, May 2012.
[22] S. C. Hung, C. H. Chiang, and Y. Li, “Circuit-simulation-based multi-objective evolutionary algorithm for design optimization of a-Si:H TFTs gate driver circuits under multilevel clock driving,” J. Display Technol., vol. 11, no. 8, pp. 640-645, Aug. 2015.
[23] C. L Lin, F. H. Chen, Y. W. Du, and M. H. Cheng, “Simplified gate driver circuit for high-resolution and narrow-bezel thin-film transistor liquid crystal display applications, ” IEEE Electron Device Lett., vol. 36, no. 8, pp. 808-810, Aug. 2015.
[24] Y. T. Tai, W. L. Pearn, K. B. Huang, and L. W. Liao, “Capability assessment for weibull in-cell touch panel manufacturing processes with variance change,” IEEE Trans. Semicond. Manuf., vol. 27, no. 2, pp. 184-191, May 2014.
[25] C. L. Lin, C. E. Wu, C. E. Lee, F. H. Chen, P. S. Chen, and M. X. Wang, “Insertion of simple structure between gate driver circuits to prevent stress degradation in in-cell touch panel using multi-V blanking method” J. Display Technol., vol. 12, no. 10, pp. 1040-1042, Oct. 2016.
[26] C. L. Lin, M. Y. Deng, C. E. Wu, P. S. Chen, and M. X. Wang, “Gate driver circuit using pre-charge structure and time-division multiplexing driving scheme for active-matrix LCDs integrated with in-cell touch structure,” J. Display Technol., vol. 12, no. 11, pp. 1238-1241, Nov. 2016.
[27] D. A. Stronks, A. Al-Dahle, and W. H. Yao, “Devices and methods for reduction of display to touch crosstalk,” United States Patent., No. 0084911, 2015.
[28] S. Y. Lee, S. C. Kim, and S. E. Pyo, “Display device with integrated touch screen and method of driving the same, ” United States Patent., No. 0320427, 2014.
[29] Y. C. Park and S. S. Hwang, “Display device having partial panels and driving method thereof, ” United States Patent., No. 0160766, 2015.
[30] S. H. Moon, I. Haruhisa, K. Kim, C. W. Park, H. J. Chung, S. H. Kim, B. K. Kim, and O. Kim, “Highly robust integrated gate-driver for in-cell touch TFT-LCD driven in time division driving method,” J. Display Technol., vol. 12, no. 5, pp. 435-441, May 2016.
[31] J. H. Lee, J. H. Kim, and M. K. Han, “A new a-Si:H TFT pixel circuit compensating the threshold voltage shift of a-Si:H TFT and OLED for active matrix OLED,” IEEE Electron Device Lett., vol.26, no. 12, pp. 897-899, Dec. 2006.
[32] B. H. You, J. H. Lee, and M. K. Han, “Polarity balanced driving scheme to suppress the degradation of Vth in a-Si:H TFT due to the positive gate bias stress for AMOLED,” J. Display Technol., vol. 3, no. 1, pp. 40-44, Mar. 2007.
[33] H. Lee, J. S. Yoo, C. D. Kim, I. J. Chung, and J. Kanicki, “Asymmetric electrical properity of corbino a-Si:H TFT and concepts of its application to flat panel displays,” IEEE Trans. Electron Devices, vol.54, no. 4, pp. 654-662, Apr. 2007.
[34] K. Tanaka, H. Kato, Y. Sugita, N. Usukura, K. Maeda, and C. Brown, “The technologies of in-cell optical touch panel with novel input functions,” J. Soc. Inf. Display, vol. 19, no. 1, pp. 70-78, 2011.
[35] C. L. Lin, C. E. Wu, P. S. Chen, P. C. Lai, J. S. Yu, C. Chang, and Y. H. Tseng, “Optical pixel sensor of hydrogenated amorphous silicon thin-film transistor free of variations in ambient illumination,” IEEE J. Solid-State Circuits, vol. 51, no. 11, pp. 2777-2785, Nov. 2016.
[36] C. L. Lin, C. E. Wu, P. S. Chen, C. H. Chang, C. C. Hsu, C. Chang, and Y. H. Tseng, “Hydrogenated amorphous silicon thin-film transistor-based optical pixel sensor with high sensitivity under ambient illumination,” IEEE Electron Device Lett., vol. 37, no. 11, pp. 1446-1449, Nov. 2016.
[37] C. Brown, B. Hadwen, and H. Kato, “A 2.6 inch VGA LCD with optical input function using a 1-transistor active-pixel sensor,” in IEEE ISSCC Dig. Tech. Papers, Feb. 2007, pp. 132-133.
[38] C. J. Brown, H. Kato, K. Maeda, and B. Hadwen, “A continuous-grain silicon-system LCD with optical input function,” IEEE J. Solid-State Circuits, vol. 42, no. 12, pp. 2904-2912, Dec. 2007.
[39] C. P. Kung, W. J. Chiang, Y. J. Chen, P. H. Wang, M. H. Wang, J. C. Ho, and C. C. Lee, “Novel flexible photo sensing pixel for large size electrophoretic display with pen writing function,” in SID Symp. Dig. Tech. Papers, Jun. 2011, vol. 42, no. 1, pp. 1822-1825.
[40] M. H. Izadi, O. Tousignant, M. F. Mokam, and K. S. Karim, “An a-Si active pixel sensor (APS) array for medical X-ray imaging,” IEEE Trans. Electron Devices, vol. 57, no. 11, pp. 3020-3026, Nov. 2010.