Capacitive touch panel with low sensitivity to water drop employing mutual-coupling electrical field shaping technique

This paper proposes a novel method to reduce the water interference on the touch panel based on mutual-capacitance sensing in human finger detection. As the height of a finger (height >10 mm) is far larger than that of a water-drop (height <1 mm), if the density distribution of electrical fiel...

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Main Authors: Zhong, Longjie, Lai, Xinquan, Xu, Donglai, Liao, Xinqin, Yang, Chuanshi, Fang, Zhongyuan, Zheng, Yuanjin
Other Authors: School of Electrical and Electronic Engineering
Format: Article
Language:English
Published: 2021
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Online Access:https://hdl.handle.net/10356/147166
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1471662021-03-24T06:41:01Z Capacitive touch panel with low sensitivity to water drop employing mutual-coupling electrical field shaping technique Zhong, Longjie Lai, Xinquan Xu, Donglai Liao, Xinqin Yang, Chuanshi Fang, Zhongyuan Zheng, Yuanjin School of Electrical and Electronic Engineering VIRTUS, IC Design Centre of Excellence Engineering::Electrical and electronic engineering Water Interference Mutual Capacitance This paper proposes a novel method to reduce the water interference on the touch panel based on mutual-capacitance sensing in human finger detection. As the height of a finger (height >10 mm) is far larger than that of a water-drop (height <1 mm), if the density distribution of electrical field of the touch panel's sensing cell is high in the high-height space (height >10 mm) and low in the low-height space (height <1 mm), the sensing cell can be designed to distinguish the finger from the water-drop. To achieve this density distribution of the electrical field, the mutual-coupling electrical field shaping (MEFS) technique is employed to build the sensing cell. The drawback of the MEFS sensing cell is large parasitic capacitance, which can be overcome by a readout IC with low sensitivity to parasitic capacitance. Experiments show that the output of the IC with the MEFS sensing cell is 1.11 V when the sensing cell is touched by the water-drop and 1.23 V when the sensing cell is touched by the finger, respectively. In contrast, the output of the IC with the traditional sensing cell is 1.32 and 1.33 V when the sensing cell is touched by the water-drop and the finger, respectively. This demonstrates that the MEFS sensing cell can better distinguish the finger from the water-drop than the traditional sensing cell does. National Research Foundation (NRF) Accepted version This work was supported in part by the National Natural Science Foundation of China (NSFC) under Grant 61771363, in part by the China Scholarship Council (CSC) under Grant 201706960042, and in part by the National Research Foundation of Singapore under Grant NRF-CRP11-2012-01. 2021-03-24T06:41:01Z 2021-03-24T06:41:01Z 2019 Journal Article Zhong, L., Lai, X., Xu, D., Liao, X., Yang, C., Fang, Z. & Zheng, Y. (2019). Capacitive touch panel with low sensitivity to water drop employing mutual-coupling electrical field shaping technique. IEEE Transactions On Circuits and Systems I: Regular Papers, 66(4), 1393-1404. https://dx.doi.org/10.1109/TCSI.2018.2879410 1549-8328 0000-0002-5707-5869 0000-0002-8319-9128 0000-0001-9455-1118 0000-0001-7772-3280 0000-0002-6499-4353 https://hdl.handle.net/10356/147166 10.1109/TCSI.2018.2879410 2-s2.0-85057429512 4 66 1393 1404 en NRF-CRP11-2012-01 IEEE Transactions on Circuits and Systems I: Regular Papers © 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. The published version is available at: https://doi.org/10.1109/TCSI.2018.2879410. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Electrical and electronic engineering
Water Interference
Mutual Capacitance
spellingShingle Engineering::Electrical and electronic engineering
Water Interference
Mutual Capacitance
Zhong, Longjie
Lai, Xinquan
Xu, Donglai
Liao, Xinqin
Yang, Chuanshi
Fang, Zhongyuan
Zheng, Yuanjin
Capacitive touch panel with low sensitivity to water drop employing mutual-coupling electrical field shaping technique
description This paper proposes a novel method to reduce the water interference on the touch panel based on mutual-capacitance sensing in human finger detection. As the height of a finger (height >10 mm) is far larger than that of a water-drop (height <1 mm), if the density distribution of electrical field of the touch panel's sensing cell is high in the high-height space (height >10 mm) and low in the low-height space (height <1 mm), the sensing cell can be designed to distinguish the finger from the water-drop. To achieve this density distribution of the electrical field, the mutual-coupling electrical field shaping (MEFS) technique is employed to build the sensing cell. The drawback of the MEFS sensing cell is large parasitic capacitance, which can be overcome by a readout IC with low sensitivity to parasitic capacitance. Experiments show that the output of the IC with the MEFS sensing cell is 1.11 V when the sensing cell is touched by the water-drop and 1.23 V when the sensing cell is touched by the finger, respectively. In contrast, the output of the IC with the traditional sensing cell is 1.32 and 1.33 V when the sensing cell is touched by the water-drop and the finger, respectively. This demonstrates that the MEFS sensing cell can better distinguish the finger from the water-drop than the traditional sensing cell does.
author2 School of Electrical and Electronic Engineering
author_facet School of Electrical and Electronic Engineering
Zhong, Longjie
Lai, Xinquan
Xu, Donglai
Liao, Xinqin
Yang, Chuanshi
Fang, Zhongyuan
Zheng, Yuanjin
format Article
author Zhong, Longjie
Lai, Xinquan
Xu, Donglai
Liao, Xinqin
Yang, Chuanshi
Fang, Zhongyuan
Zheng, Yuanjin
author_sort Zhong, Longjie
title Capacitive touch panel with low sensitivity to water drop employing mutual-coupling electrical field shaping technique
title_short Capacitive touch panel with low sensitivity to water drop employing mutual-coupling electrical field shaping technique
title_full Capacitive touch panel with low sensitivity to water drop employing mutual-coupling electrical field shaping technique
title_fullStr Capacitive touch panel with low sensitivity to water drop employing mutual-coupling electrical field shaping technique
title_full_unstemmed Capacitive touch panel with low sensitivity to water drop employing mutual-coupling electrical field shaping technique
title_sort capacitive touch panel with low sensitivity to water drop employing mutual-coupling electrical field shaping technique
publishDate 2021
url https://hdl.handle.net/10356/147166
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