• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.567-570
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• 2004

We have designed a single gap transflective liquid crystal display (LCD) driven by a fringe electric field, in which the LCs are homogeneously aligned in the initial state. In the reflective and transmissive areas, the degrees of the rotation of the LC director are $22.5^{\circ}$ and $45^{\circ}$, respectively. Utilizing this mechanism and an in-cell retarder with a quarter-wave plate that is used below the LC layer, the transflective LCD using fringe-field switching (FFS) mode is realized.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.415-418
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• 2005

To understand effects of carbon nanotubes (CNTs) dispersed in nematic liquid crystal (NLC) on electro-optic characteristic and orientation of the LC, we CNT-doped homogeneously-aligned NLC cells driven by in-plane field have been fabricated. The CNTs were aligned with a LC director from the initial state to below critical ac field, whereas the CNTs disturbed the LC director field above critical ac field. We observed motional textures in the form of vertical stripes in the local area between electrodes, which were associated with a deformation of the LC director orientation. This indicates that CNTs start vibrating three dimensionally with translational motion. Further, the hysterisis studies of voltage-dependent transmittance under dc electric field show that the amount of residual dc, which is related to image sticking problem in liquid crystal displays, is greatly reduced due to ion trapping by CNTS while keeping operating voltage and response time about the same compared to the un-doped LC cell.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.520-521
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• 2005

To observe the orientation of carbon nanotubes (CNTs) dispersed in nematic liquid crystal (NLC), CNT-doped homogeneously-aligned NLC cells driven by in-plane field was fabricated. The CNTs were aligned with a LC director in the initial state, whereas the CNTs disturbed the LC director above critical ac field. We observed motional textures in the form of vertical stripes in the local area between electrodes, which were associated with a deformation of the LC director orientation. This suggests that CNTs start to vibrate three dimensionally with translational motion. The hysteresis studies of voltage-dependent transmittance under dc electric field show that the amount of residual dc is greatly reduced due to ion trapping by CNT.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.1197-1199
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• 2004

We have studied an optically compensated splay (OCS) mode driven by fringe electric field. The OCS configuration obtained by applying voltage to vertically aligned LCs shows a dark state when an optic axis of the OCS cell coincides with one of crossed polarizer axis. When the fringe electric field is applied, the LC director rotates in plane above whole electrode surface, giving rise to the high transmittance, the low operating voltage and wide viewing angle simultaneously.

• 한국전기전자재료학회논문지
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• 제32권2호
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• pp.141-146
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• 2019

Non-emissive LCDs need a backlight, and have difficulty implementing wide viewing angles due to differences in phase retardation depending on the behavior of the liquid crystals. Although wide viewing angles are good characteristics for devices such as TVs, they are not good for mobile devices. In this paper, we propose ways to design diffusers with ELC lenses to achieve wide and narrow viewing angles depending on the circumstances. A study was conducted on optimizing the design of a liquid lens diffuser with the same light as that for an OLED, by extracting design factors that affect the performance of the diffuser and applying the Taguchi method to them.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.288-288
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• 2009

We have studied polarity effects of dielectric anisotropy effects on electro-optical characteristics of a twisted nematic mode driven by fringe electric field, which has wide viewing angle characteristics. Our device is designed as normally black mode between parallel polarizers. The perfect polarization conversion of incident light, which passes through a polarizer, is achieved, when it passes through the twisted liquid crystal (LC) layer. If an electric field is applied, the LC molecules with a positive (or negative) dielectric anisotropy rotate parallel (or perpendicular) to the horizontal component of a fringe electric field as increasing transmittance. From the calculated results, enhanced transmittance of the fringe field-twisted nematic (FF-TN) mode with positive dielectric anisotropy of + 8.2 can be obtained.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.104-108
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• 2005

We have studied electrode-optic characteristics of IPS (in-plane switching) mode with electrode on top substrate. Because the IPS mode does not have electrode on top substrate. it shows not only slow response time due to weak electric field but also slow discharging problem when electrostatic field is generated after fabricating the cell. To solve these problems. we have formed additional electrode including dielectric layer in the inner part of the cell and studied electrode-optic characteristics of new IPS cell by changing thickness of dielectric layer.

• 한국전기전자재료학회논문지
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• 제16권3호
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• pp.224-230
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• 2003

The voltage-dependent transmittance curve of a homogeneously aligned liquid crystal (LC) cell driven by fringe-electric field(named FFS mode) was studied, while changing dielectric anisotropy of a LC. The results show that for a LC with positive dielectric anisotropy while positioning at initial position. Therefore, we conclude that the dynamic stability is strongly dependent on the types of the LCs and voltage-dependent dynamics of the LC with negative dielectric anisotropy is staler than that of the LC with positive dielectric anisotropy in the FFS mode.

• 한국전기전자재료학회논문지
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• 제26권6호
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• pp.457-461
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• 2013

In this paper, a novel method based on geometrical optics is proposed to calculate the optical characteristics of an electric field driven liquid crystal (ELC) lens. For an optimally designed ELC lens, effective refractive index is calculated and then ray tracing is carried out using Huygens' principle. From the results, the intensity distribution at the optimum viewing distance (OVD) is obtained. To confirm the validity of our work, the result is compared with that calculated by the extended Jones matrix method (EJMM). As a result, it turns out that the novel method provides more simple and rigorous simulation results than the EJMM.

• Elastomers and Composites
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• 제47권4호
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• pp.282-291
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• 2012

최근 들어 광, 온도, pH, 전기, 자성, 압력 등과 같은 외부 환경의 작은 변화에도 반응하여 모양/부피가 변하거나 기계적, 광학적, 전기적, 화학적 특성 등이 가역적으로 바뀌는 스마트 소재에 대한 관심이 높아지고 있다. 이러한 스마트 소재들 중 광조사에 의해 소재의 다양한 특성을 가역적으로 제어할 수 있는 광응답 스마트 소재가 많은 관심을 받고 있다. 본 논문에서는 광에너지를 받아 기계적 에너지로 바로 전환되어 인공근육, 모터 등과 같은 액츄에이터 기능을 할 수 있는 광구동형 스마트 고분자 소재들에 대해 소개하고자 한다. 특히, 광구동형 스마트 고분자 소재 중에서도 마이크로와 매크로 스케일 변형이 가능한 아조벤젠을 함유한 비결정성 고분자, 액정 고분자, 자기 조립형 초분자에 대한 다양한 연구들에 대해 설명하고자 한다.