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http://dx.doi.org/10.6109/jkiice.2015.19.4.895

Frequency Division Concurrent Sensing Method for High-Speed Detection of Large Touch Screens  

Jang, Un-Yong (School of Electrical Engineering, Chungbuk National University)
Kim, HyungWon (School of Electrical Engineering, Chungbuk National University)
Publication Information
Journal of the Korea Institute of Information and Communication Engineering / v.19, no.4, 2015 , pp. 895-902 More about this Journal
Abstract
This paper presents a high-speed sensing and noise cancellation technique for large touch screens, which is called FDCS (Frequency Division Concurrent Sensing). Most conventional touch screen detection methods apply excitation pulses sequentially and analyze the sensing signals sequentially, and so are often unacceptably slow for large touch screens. The proposed technique applies sinusoidal signals of orthogonal frequencies simultaneously to all drive lines, and analyzes the signals from each sense line in frequency domain. Its parallel driving allows high speed detection even for a very large touch screens. It enhances the sensing SNR (Signal to Noise Ratio) by introducing a frequency domain noise filtering scheme. We also propose a pre-distortion equalizer, which compensates the drive signals using the inverse transfer function of touch screen panel to further enhance the sensing SNR. Experimental results with a 23" large touch screen show that the proposed technique enhances the frame scan rate by 273% and an SNR by 43dB compared with a conventional scheme.
Keywords
Large touch screen controller; Orthogonal frequency division; Noise Cancellation; Pre-distortion equalizer;
Citations & Related Records
Times Cited By KSCI : 2  (Citation Analysis)
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1 H. R. Kim, Y. K. Choi, San-Ho Byun, Sang-Woo Kim, Kwang-Ho Choi, Hae-Yong Ahn, Jong-Kang Park, Dong-Yul Lee, Zhong-Yuan Wu, Hyung-Dal Kwon, Yong-Yeob Choi, Chang-Ju Lee, Hwa-Hyun Cho, Jae-Suk Yu, Myunghee Lee, "A Mobile-Display-Driver IC Embedding a Capacitive-Touch-Screen Controller System", in Proc. of ISSCC 2010, pp.114-116, San Francisco, 8 Feb. 2010.
2 U. Y. Jang, H. W. Kim, T. W. Cho, H. G. Jang, S. W. Lee, "Architecture of Multi Purpose Touch Screen Controller with Self Calibration Scheme", in Proc. of IEEK Fall Conference 2013, pp.162-166, Seoul, Korea, Nov. 2013.
3 H. C. Shin, S. H. Ko, H.J. Jang, I. H. Yun, and K. Y. Lee, "A 55dB SNR with 240Hz frame scan rate mutual capacitor 30$\times$24 touch-screen panel read-out IC using code-division multiple sensing technique," in Proc. of IEEE International Solid-State Circuits Conference Digest of Technical Papers (ISSCC), pp. 388-389, San Francisco, USA, Feb. 2013.
4 Y. H. Tai, H. L. Chiu, and L. S. Chou, "Large-Area Capacitive Active Touch Panel Using the Method of Pulse Overlapping Detection," Journal of Display Technology, Vol. 9, no. 3, pp. 170-175, March 2013.   DOI
5 J. S. Lee, D. H. Yeo, J. Y. Um, E. W. Song, J. Y. Sim, H. J. Park, S. M. Seo, M. H. Shin, D. H. Cha, H. S. Lee, "A 10-Touch Capacitive-Touch Sensor Circuit with the Time-Domain Input-Node Isolation", SID 2012 DIGEST, Vol.43, Issue 1, pp.493-496, June 2012.
6 I. S. Yang and O. K. Kwon, "A Touch Controller Using Differential Sensing Method for On-Cell Capacitive Touch Screen Panel Systems", IEEE T-CE, Vol. 57, No.3, pp.1027-1032, Aug 2011.
7 T. H. Hwang, W. H. Cui, I. S. Yang, and O. K. Kwon, "A Highly Area-Efficient Controller for Capacitive Touch Screen Panel Systems", IEEE T-CE, Vol. 56, No.2, pp.1115-1122, May 2010.
8 M.G.A. Mohamed. H. W. Kim, and T. W. Cho, "Efficient Multi-Touch Detection Algorithm for Large Touch Screen Panels," IEIE Transactions on Smart Processing and Computing, Vol. 3, no. 4, pp. 246-250, August 2014.   DOI
9 M.G.A. Mohamed, U.Y Jang, I.C Seo, H. W. Kim, T. W. Cho, H. G. Jang, S. O. Lee, "Efficient Algorithm for Accurate Touch Detection of Large Touch Screen Panels", in Proc. of ISCE 2014, pp.243-244, Jeju, Korea, 22-25 Jun.2014.
10 I. C. Seo, U. Y. Jang, M.G.A. Mohamed, T. W Cho, and H. W. Kim, H. K. Chang and S. O. Lee, "Voltage shifting Double Integration Circuit for High Sensing Resolution of Large Capacitive Touch Screen Panels", in Proc. of ISCE 2014, pp.241-242, Jeju, Korea, 22-25 Jun.2014.
11 Chungbuk national university industry-academic cooperation foundation, Kortek corporation, "Touch screen detection apparatus using voltage-shifting double-sided integrator with automatic level calibration", Korea, patent application number 10-2014-0080811, Jun.30.2014.
12 I. C. Seo, T. W. Cho, H. W. Kim, H. G. Jang, S. O. Lee, "Frequency Domain Concurrent Sensing Technique for Large Touch Screen Panels", in Proc. of IEEK Fall CONFERENCE 2013, pp.55-58, Seoul Korea, 23 Nov. 2013.
13 ATMEL Corporation, "Touch Sensors Design Guide, 10620 D-AT42" Sept. 2004.
14 S. H. Ko, H, C. Shin, J. M. Lee, H. J. Jang, K. Y. Lee, "Low Noise Capacitive Sensor for Multi-touch Mobile handset's applications", in Proc. of ASSCC 2010, pp.247-250, Beijing China, 8-10 Nov. 2010.
15 K. S. Byun, B. W. Min, "Circuit Modeling and Analysis of Touch Screen Panel", KIEES, Vol 25, Num1, pp.47-52, Jan. 2014.