For the first time, we analyze the mechanism of electromagnetic interference (EMI) in an advanced in-cell touch (AIT) panel, which is a state-of-the-art in-cell touch screen panel technology. The AIT panel has stronger EMI generation at a specific frequency band (0.15 30 MHz) due to a load free driving (LFD) method. The LFD is adopted to overcome the structural vulnerability of in-cell touch panel, which incurs large parasitic capacitance due to the touch electrodes within the display panel. In order to overcome the EMI problem, we present a novel driving method using pseudo random pulse (PRP). The power spectrum of PRP is well spread over the frequency band, resulting in a lower EMI. We measured the EMI level with a near-field probe, and the proposed driving method shows the EMI reduction of 6.5 dB. This EMI reduction is accomplished without structural reconfiguration, as well as the touch performance remains the same as that before PRP is applied. Therefore, the proposed driving method can be utilized in the field of automotive, military, and aviation industries as a user interface which requires high touch performance and low EMI generation due to the peculiarities.
Bibliographical noteFunding Information:
Manuscript received January 14, 2018; revised February 28, 2018; accepted March 5, 2018. Date of publication March 7, 2018; date of current version April 9, 2018. This work was supported in part by MSIP, Korea, under the ITRC (IITP-2017-2014-0-00729) supervised by the IITP, and in part by LG Display Company Ltd., under Yonsei Incubation Program. The associate editor coordinating the review of this paper and approving it for publication was Prof. Ravinder S. Dahiya. (Corresponding author: Byung-Wook Min.) The authors are with the Department of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749, South Korea (e-mail: firstname.lastname@example.org). Digital Object Identifier 10.1109/JSEN.2018.2813005 Fig. 1. EMI compliance testing result of a 7-inch AIT panel by LG Display Co., Ltd.
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All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering