• 한국전기전자재료학회논문지
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• 제25권8호
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• pp.651-656
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• 2012

A study on capacitive characteristics of stylus pen for touch panel are progressed in this paper. Also the main factors for capacitive sensitivity are studied. Namely, highly sensitive stylus pen which can be applied to capacitive touch panel are studied based on the analysis of materials and process conditions regardless of pattern shapes. Stylus pen was made of PDMS(Poly-Di-Methyl-Siloxane) and conductive metal powders which does not damage the touch panel surface. We tried to get the advantages of both the properties of soft PDMS and conductive metal powders. We found that potential difference of capacitance change with conductivity of the composite materials(PDMS + metal powders) it implies that during touch process, large voltage difference can be caused by the high conductive materials of stylus pen. Stylus pen made by PDMS with mixed with Ag powders which has large conductivity shows more capacitance change of 1 pF than PDMS with other materials of Ni or C powders.

• 반도체디스플레이기술학회지
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• 제13권1호
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• pp.83-90
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• 2014

Using a ray tracing simulation, we have investigated the moir${\acute{e}}$ and starburst phenomena of touch screen panels (TSPs) based on opaque metallic grids (square, hexagonal, and random grids). It is demonstrated that employing a random metal mesh is the most effective way to suppress the moir${\acute{e}}$ and starburst phenomena at the same time. At high crossing angles between metal mesh of TSPs and black matrix (BM) of displays, however, a random metal mesh brings in stronger moir${\acute{e}}$ phenomenon than a square metal mesh due to point defects. Though the square metal mesh suppresses the moir${\acute{e}}$ effect substantially at high crossing angles, yet it results in the strongest starburst patterns. We have also provided the simulation scheme that can capture the moir${\acute{e}}$ and starburst patterns observed experimentally and useful design guidelines for metal grids.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권3호
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• pp.380-386
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• 2016

This paper presents a compact and low-power on-chip touch sensor and readout circuit using shunt proximity touch sensor and its design scheme. In the proposed touch sensor readout circuit, the touch panel condition depending on the proximity of the finger is directly converted into the corresponding voltage level without additional signal conditioning procedures. Furthermore, the additional circuitry including the comparator and the flip-flop does not consume any static current, which leads to a low-power design scheme. A new prototype touch sensor readout integrated circuit was fabricated using complementally metal oxide silicon (CMOS) $0.18{\mu}m$ technology with core area of $0.032mm^2$ and total current of $125{\mu}A$. Our measurement result shows that an actual 10.4 inches capacitive type touch screen panel (TSP) can detect the finger size from 0 to 1.52 mm, sharply.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 추계학술대회 논문집
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• pp.287-288
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• 2015

최근 투명 산화물 전극 (TCO)은 LED, electronic display, solar cell, touch screen panel (TSP) 등 다양한 분야에 많이 사용되고 있다. TCO는 높은 광 투과도와 전도성으로 인해 여러 분야에 많이 사용되고 있으며, 특히 ITO (Sn-doped indium oxide)가 display 분야에 많이 적용되고 있다. 하지만, ITO는 투과도와 면저항의 반비례 관계를 가지므로 더 낮은 면저항이 요구되는 대면적 TSP 분야에 적용되기에는 많은 개선이 필요하다. 따라서, 본 연구에서는 metal mesh film의 연구를 통해 TSP 분야에 사용되는 ITO를 대체하고자 한다. 제작된 mesh film은 모두 면저항은 $15{\Omega}/{\square}$ 이하, 광 투과도 90% (@550nm) 이상을 나타내었다.

• 한국표면공학회지
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• 제49권6호
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• pp.575-579
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• 2016

The metal mesh films with thickness of 1.0, 1.5, $2.0{\mu}m$ were prepared by photolithography using Ag, Al, and Cu metals. Every metal films were showed C(111) preferred orientation and Ag showed the lowest resistivity and followed by Al and Cu. The transmittance of almost films were higher than 90%. But, the Ag film with thickness of $2.0{\mu}m$ was delaminated during photolithography process due to low adhesion. So, Cu and Ti metal films were introduced under Ag film to improve adhesion property. The Cu film showed higher adhesion properties compared to Ti film. Furthermore, the Ti films that deposited on Ag film showed higher acid resistance.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.578-583
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• 2017

본 논문은 최근에 모바일 기기에 적용되고 있는 차세대 터치 기술로서 압력터치 센서를 이용한 3D 터치패드 기술에 관한 것이다. 3D터치 기술은 터치 위치 및 터치 압력을 동시에 검출할 수 있고 멀티터치 기능이 있어야 한다. 본 논문의 목적은 스트레인 게이지를 이용하여 압력터치 센서를 제작하고 2점을 동시에 터치 가능한 압력터치 패드 제작이다. 하드웨어 부분은 터치 인식 센서에 금속 박막형 스트레인 게이지를 이용하였고 각 스트레인 게이지 센서마다 휘스톤 브리지 회로로 미세한 터치 신호를 검출하였다. 또한, 터치 신호 증폭기를 사용하여 터치 신호를 증폭하고 마이크로프로세서를 통해 디지털 데이터로 변환하여 화면에 디스플레이하는 터치 인식 시스템을 만들었다. 소프트웨어 부분은 2점 동시터치가 가능하고 터치 압력에 따라 구별 가능한 터치 인식 알고리즘을 C언어로 제작하였다. 터치 강도와 터치 위치가 다른 두 개의 터치 신호를 동시에 검출하여 화면에 나타내는 실험을 성공적으로 수행하였다. 본 연구를 통해 스트레인 게이지를 이용한 터치 인식 방법으로 3D 터치패드의 응용 가능성을 확인하였다.

• Journal of information and communication convergence engineering
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• 제13권3호
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• pp.189-196
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• 2015

In this paper, we present a rotating auto-zeroing offset cancellation technique, which can improve the performance of touch screen sensing circuits. Our target touch screen detection method employs multiple continuous sine waves to achieve a high speed for large touch screens. While conventional auto-zeroing schemes cannot handle such continuous signals properly, the proposed scheme does not suffer from switching noise and provides effective offset cancellation for continuous signals. Experimental results show that the proposed technique improves the signal-to-noise ratio by 14 dB compared to a conventional offset cancellation scheme. For the realistic simulation results, we used Cadence SPECTRE with an accurate TSP model and noise source. We also applied an asymmetric device size (10% MOS size mismatch) to the OP Amp design in order to measure the effectiveness of offset cancellation. We implemented the proposed circuit as part of a touch screen controller system-on-chip by using a Magnachip/SK Hynix 0.18-µm complementary metal-oxide semiconductor (CMOS) process.

• 한국강구조학회 논문집
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• 제16권5호통권72호
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• pp.599-607
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• 2004

건물이 고층화되어 가면서 철골구조 사용이 빈번해지고 있으며 철골구조물의 큰 축력을 받는 기둥에 있어서 이음부 설계가 중요한 문제가 되고 있다. 한편, 미국 AISC 기준에서는 기둥이음에서 지압내력으로 모든 압축축력을 전달할 수도 있으나, 우리나라 기준에서는 소요압축축력의 1/4만을 접촉면에 의해 직접전달 시킬 수 있다고 제한함에 따라 메탈터치를 활용한 기둥이음에 대한 새로운 방법의 개발이 제한되고 있는 실정이다. 따라서 본 논문에서는 기존 볼트, 용접 체결된 실험체에 이음부 틈의 크기를 매개변수로 하는 실험체의 응력전달체계를 규명하고, 메탈터치 정도에 따른 철골기둥 이음부의 압축축력전달 메카니즘을 검증한다. 또한 해석과 실험을 통하여 틈의 크기에 따른 거동 양상을 파악하여 메탈터치에 의한 이음부에서의 응력전달체계에 대한 확인과 이론적 기초를 제시하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1147-1148
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• 2015

This study demonstrates the coating effect of carbon nanotubes on metal meshes, which have been made with various line-spaces and line-width, for touch screen panels. The CNTs have been deposited on metal meshes via electrophoretic deposition (EPD). The sheet resistances, visible transmittances, visible reflectances have been measured before and after electrophoretic deposition. The experimental results confirm that CNT coating metal meshes with various line-spaces and line width can satisfy the requirements that are required for transparent electrodes of touch screen panels.

• JSTS:Journal of Semiconductor Technology and Science
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• 제10권4호
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• pp.300-308
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• 2010

This paper describes the development of a low-power electrocardiogram (ECG) touch sensor intended for the use with two dry metal electrodes. An equivalent ECG extraction circuit model encountered in a ground-free two-electrode configuration is investigated for an optimal sensor read-out circuit design criteria. From the equivalent circuit model, (1) maximum sensor resolution is derived based on the electrode's background thermal noise, which originates from high electrode-skin contact impedance, together with the input referred noise of instrumentation amplifier (IA), (2) 60 Hz electrostatic coupling from mains and motion artifact are also considered to determine minimum requirement of common mode rejection ratio (CMRR) and input impedance of IA. A dedicated ECG read-out front end incorporating chopping scheme is introduced to provide an input referred circuit noise of 1.3 ${\mu}V_{rms}$ over 0.5 Hz ~ 200 Hz, CMRR of IA > 100 dB, sensor resolution of 7 bits, and dissipating only 36 ${\mu}W$. Together with 8 bits synchronous successive approximation register (SAR) ADC, the sensor IC chip is implemented in 0.18 ${\mu}m$ CMOS technology and integrated on a 5 cm $\times$ 8 cm PCB with two copper patterned electrodes. With the help of proposed touch sensor, ECG signal containing QRS complex and P, T waves are successfully extracted by simply touching the electrodes with two thumbs.