• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 및 기술 세미나 논문집 디스플레이 광소자
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• pp.44-44
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• 2008

To date, rubbing has been widely used to align LC molecules uniformly. Although rubbing can be simple, it has fundamental problems such as the generation of defects by dust and static electricity, and difficulty in achieving a uniform LC alignment on a large substrate. Therefore, non contact alignment has been investigated. Ion beam induced alignment method, which provides controllability, nonstop process, and high resolution display. In this study, we investigated liquid crystal (LC) alignment with ion beam (IB) that non contact alignment technique on polyimide and electro-optical characteristics of twisted nematic (TN)-liquid crystal display (LCD) on the polyimide under various ion beam angles. In this experiment, Polyimide layer was coated on glass by spin-coating and Voltage-transmittance(VT) and response time characteristics of the TN cell were measured by a LCD evaluation system. The good characteristics of the nematic liquid crystal (NLC) alignment with the ion beam exposure polyimide surface was observed. The tilt angle of NLC on the PI surface with ion beam exposure can be measured under $1^{\circ}$ for all of irradiation angles. In addition, it can be achieved the good EO properties, and residual DC property of the ion beam aligned TN cell on polyimide surface.

• 한국수소및신에너지학회논문집
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• 제23권6호
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• pp.678-687
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• 2012

Concentration fields of solid powder in a liquid fuel were quantitatively measured by a visualization technique. The measurement system consists of a camcoder and three LCD monitors. The solid powder (glass powder) were filled in a head tank which was installed over a main mixing tank ($D{\times}H$, $310{\times}370mm$). The main mixing tank was filled with JetA1 fuel oil. With a sudden opening of the upper tank by pressurized nitrogen gas with 1.9 bar, the solid powder were poured into the JetA1 oil. An impeller type agitator was being rotated in the mixing with 700 rpm for the enhancements of mixing. Uniform visualization for the mixing flow field was made by the light from the three LCD monitors, and the visualized images were captured by the camcoder. The color images captured by the camcoder The color information of the captured images was decoded into three principle colors R, G, and B to get quantitattive relations between the concentrations of the solid powder and the colors. To get better fitting for the strong non-linearity between the concentration and the color, a neural network which has strong fitting performances was used. Analyses on the transient mixing of the solid powders were quantitatively made.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.329-329
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• 2008

To date, rubbing has been widely used to align LC molecules uniformly. Although rubbing can be simple, it has fundamental problems such as the generation of defects by dust and static electricity, and difficulty in achieving a uniform LC alignment on a large substrate. Therefore, noncontact alignment has been investigated. Ion beam induced alignment method, which provides controllability, nonstop process, and high resolution display. In this study, we investigated liquid crystal (LC) alignment with ion beam (IB) that non contact alignment technique on polyimide and electro-optical characteristics of twisted nematic (TN)-liquid crystal display (LCD) on the poly imide under various ion beam angles. In this experiment, Polyimide layer was coated on glass by spin-coating and Voltage-transmittance(VT) and response time characteristics of the TN cell were measured by a LCD evaluation system. The good characteristics of the nematic liquid crystal (NLC) alignment with the ion beam exposure poly imide surface was observed. The tilt angle of NLC on the PI surface with ion beam exposure can be measured under $1^{\circ}4 for all of irradiation angles. In addition, it can be achieved the good ED properties, and residual DC property of the ion beam aligned TN cell on polyimide surface.

• 제어로봇시스템학회논문지
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• 제14권5호
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• pp.415-419
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• 2008

Detecting and correcting defects on LCD glasses early in the manufacturing process becomes important for panel makers to reduce the manufacturing costs and to improve productivity. Many attempts have been made and were successfully applied to detect and identify simple defects such as scratches, dents, and foreign objects on glasses. However, it is still difficult to robustly detect low-contrast defect region, called Mura or blemish area on glasses. Typically, these defect areas are roughly defined as relatively large, several millimeters of diameter, and relatively dark and/or bright region of low Signal-to-Noise Ratio (SNR) against background of low-frequency signal. The aim of this article is to present a robust algorithm to segment these blemish defects. Early 90's, a highly robust estimator, known as the Model-Fitting (MF) estimator was developed by X. Zhuang et. al. and have been successfully used in many computer vision application. Compared to the conventional Least-Square (LS) estimator the MF estimator can successfully estimate model parameters from a dataset of contaminated Gaussian mixture. Such a noise model is defined as a regular white Gaussian noise model with probability $1-\varepsilon$ plus an outlier process with probability $varepsilon$. In the sense of robust estimation, the blemish defect in images can be considered as being a group of outliers in the process of estimating image background model parameters. The algorithm developed in this paper uses a modified MF estimator to robustly estimate the background model and as a by-product to segment the blemish defects, the outliers.

• 대한전자공학회논문지TE
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• 제39권2호
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• pp.11-16
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• 2002

본 논문은 백색유기발광소자를 구현하기 위해서 빛의 3원색인 적, 녹, 청색의 형광색소를 적절하게 배합하여 단일층 백색광을 얻었다. 개별적인 적색, 녹색, 청색 유기고분자 발광소자의 성능이 가장 우수한 특성을 조사한 후 최적화된 값으로 백색유기발광소자를 제작하였다. PVK와 Bu-PBD를 각각 70wt%, 30wt%로 혼합한 용액에 Nile Red(0.015mol%), Coumarin6(0.04mol%), TPB(3mol%)를 각각 첨가하여 백색발광소자를 제작하였을 때 구동전압이 20V에서 휘도 785cd/$m^2$, 색좌표가 (0.32, 0.34)인 백색광을 얻었다

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.241-245
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• 2006

EEFL(External Electrode Fluorescent Lamp) for LCD displays are analyzed on electrical and optical characteristics by various electrode length. The electrodes of EEFL are coated at the outside of the glass tube. Brightness and efficiency of the EEFL are affected on lamp impedance characteristic. So, the experimental models are proposed for analysis and measurements of the brightness and efficiency of the lamps according to the electrode length. The sample of LCD backlight unit is used for these experiments, EEFL arrayed BLU of 32' for commercial TV display. The parameters of the experiments were quantised for simple result reading as the length of electrodes as 15, 23 and 30 mm. The inverter was designed and manufactured in the laboratory as the Full-Bridge switching inverter. The feature of the output were measured on voltages about 1000 - 1400V at the currents of 11 - 29 mA and the brightness $15,000\;cd/m^2-40,000\;cd/m^2$. The experiments have shown that the brightness are increased by increasing of the electrode lengths which have the lamp currents increased. But at an certain conditions, the brightness and efficiency were decreased because of unmatched between the inverter output and lamp impedance. The optimum applications of the EEFL BLU of 32' in this experiments have been shown to choose the parameters for driving frequencies of 100 kHz - 150 kHz, the brightness of $18,000-19,000\;cd/m^2$ and efficiencies of 40 - 45 lm/w.

• 한국정보전자통신기술학회논문지
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• 제16권2호
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• pp.109-115
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• 2023

본 논문은 UV(ultraviolet) 처리된 자기 조립 단분자막(fluorinated self-assembled monolayers; FSAM)을 배향막으로 사용한 액정의 배향 특성을 분석하였다. 물리화학적 분석을 사용하여 UV 처리 전후의 ITO(indium-tin-oxide) 유리 기판의 FSAM 특성을 확인하였다. FSAM 표면은 UV 처리에 의해 소수성에서 친수성으로 변화하였다. LC(liquid crystal) 분자는 UV 처리된 FSAM 표면에서 수평방향으로 정렬되었고 선경사각도 90°에서 0°로 변화하였다. UV 처리된 FSAM을 배향막으로 사용하여 제작된 TN(twist nematic) 셀의 전기광학(electro optics; EO) 특성은 기존의 PI(polyimide) 배향막에 비해 응답 시간이 빠른 것을 확인하였다. 이는 UV 처리된 FSAM 이 LCD(liquid crystal display)의 기존 폴리이미드 배향막을 대체할 잠재적인 가능성을 가진다.

• 한국광학회지
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• 제28권6호
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• pp.356-360
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• 2017

ITO는 높은 전기 전도도와 가시광선, 근적외선 영역에서 투명성을 가진다. LCD, OLED 등을 포함한 광학에 적용되는 부품들의 제조에 투명전극으로 ITO가 사용되고 있다. 가시광선 영역에서의 투명성과 높은 전도도 때문에 다양한 전기, 디스플레이 센서의 전극으로 이용되었다. 한 가지 사안은 기판의 특성에 충격없이 ITO, 금속 필름같은 특정한 영역의 층을 제거하는 부분이다. 레이저를 사용한 유리 위의 ITO 제거는 기존 방법에 비해 친환경적이다. 본 연구는 펨토초 레이저와 나노초 레이저를 사용하여 ITO를 제거하는 비교분석이다.

• 자원리싸이클링
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• 제22권3호
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• pp.50-56
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• 2013

폐 디스플레이에서 발생하는 플라스틱을 재활용하여 실용적이고 경제성 있는 재생복합소재의 개발에 기여할 목적으로 ABS/PE(50/50과 20/80), ABS/GF (90/10) 복합 소재의 조성이 연신율에 미치는 효과를 연구하였다. PE 함량을 50%에서 80%로 증가시킨 폐플라스틱 재생복합소재의 인장시험 결과 전반적으로 연신율이 2.4%에서 13%로 증가하는 것이 관찰되었으나 유리섬유 첨가 시 인장강도와 연신율 모두 현저하게 감소하였다. 이러한 사실에 비추어 볼 때 PE의 함량에 따라 인장강도 등 다양한 기계적 특성의 조절이 가능함을 알 수 있었고 무엇보다도 플라스틱 사출성형에 투입되는 재생복합소재의 특성 중 아주 중요한 연신율을 향상시키는데 PE의 효과가 현저함을 알 수 있었다. 이는 ABS 자체의 우세한 비정질성이 결정성을 띈 PE의 첨가로 인해서 광범위하게 결정화된 결과 폐플라스틱 입자들 사이의 전단 응력이 감소하기 때문인 것으로 간주된다.

• 한국안광학회지
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• 제7권2호
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• pp.155-161
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• 2002

전도성 혹은 비전도성 지지체에서 전기변색이 가능한 수 nm에서 수액 nm 두께의 금속 니켈 박막 형성에 대한 연구를 수행하였다. 광학렌즈나 혹은 LCD에 사용되는 ITO, 실리콘 웨이퍼에 박막 형성에 대한 연구는 다양한 두께의 니켈 박막은 자체로서의 응용 가능성 뿐 아니라, 광전기화학 소자, 특히 선글라스로 대변되는 변색 소자에의 응용 가능성이 아주 크다. 이러한 소자들은 나노 기술 응용과 양자점의 응용 등으로 경박단소형의 렌즈나 전지, 유리 그리고 태양 선지 등에 응용이 가능하다. 전기화학적으로 니켈 금속을 ITO 유리위에 코팅한 후, AFM, XRD을 이용하여 미세구조를 확인하고, 순환전압전류법, 시간대전류법, 임피던스를 이용하여 이들의 전기화학적 박막 특성을 조사하였다.