• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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• pp.279-280
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• 2005

We have designed a single gap transflective liquid crystal display (LCD) driven by a fringe electric field and vertical field. The conventional FFS mode does not have an 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, transflective LCD with ITO coated upper substrate was suggested but the transmittance was reduced significantly due to effects from vertical field. Hence, in the present paper, new transflective LCD with ITO coating only in the reflective region was characterized.

• 한국광학회지
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• 제13권2호
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• pp.166-170
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• 2002

본 연구에서 우리는 반사형 LCD용 반사판을 최적화하고자 한다. 반사판의 새로운 표면구조를 체계적인 수식적 접근 및 분석을 통해 구한 후, 반사특성의 결과를 바탕으로 기존의 표면구조와 비교해서 보다 최적화된 표면구조를 제시하고자 한다. 반사특성의 결과로는 새로운 표면구조가 기존의 표면구조에 비해 동일한 시야각 범위에서 보다 균일한 반사율 분포를 나타내고 있으며, 또한 주변환경을 충분히 고려해서 사용자 위주의 자유로운 시야각 범위 조절이 가능함을 알 수 있다. 결과적으로, 새로운 표면구조는 보다 균일한 반사율 분포를 가지게 됨으로써, 기존의 반사형 LCD의 시야각 의존성을 상당부분 개선할 수 있으리라 본다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1080-1082
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• 2008

An ultra-thin reflective flexible LCD film has been demonstrated. The 30% thickness of the display can be reduced by applying a quarter-wave-plate film as upper substrate. A low temperature alignment material and special designed photo spacer were applied in this new display. The bending behavior was improved by reduced thickness.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.625-630
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• 2006

A new method to get reliable viewing angle measurements on LCD reflective display is presented. This method is based on the use of commercial Fourier optics viewing angle instruments already proposed by ELDIM for more than 15 years. This apparatus is capable to measure simultaneously quasi all the incidence and azimuth angles and to control very precisely the illumination of the sample. We show that, in contrast to other instruments, a clever illumination procedure with two different conditions allows separation of the intrinsic reflective contribution of the display and of the parasitic front end reflection. In this way, intrinsic performances of the display can be obtained at any incidence and azimuth angles and realistic observer conditions can be simulated.

• 한국전기전자재료학회논문지
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• 제25권7호
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• pp.525-530
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• 2012

We present the results of a study of the polarizing photovoltaic (PV) effects in an aligned polymer bulk heterojuction PV layer. The fairly uniform in-plane uniaxial alignment of the PV layer with a macroscopic axial orientational order parameter of 0.40 was achieved by means of a simple rubbing technique. Moreover, reflective polarizing PSCs having the aligned PV layers were applied to power-generating reflective type liquid crystal displays (LCDs), which exhibited a maximum contrast ratio of 1.7. These results form a promising foundation for various energy harvesting polarization dependent opto-electrical LCD device applications.

• Journal of Information Display
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• 제4권2호
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• pp.25-28
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• 2003

We propose a new optical configuration of a hybrid-aligned nematic liquid crystal cell for reflective displays, which consist of a biaxial film for obtaining wide viewing angle and a half-wave film for achieving high contrast. As a result, we can achieve wide viewing angle of (80( for the horizontal direction and (50( for the vertical direction and uniform reflection spectrum.

• 한국안광학회지
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• 제19권3호
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• pp.339-344
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• 2014

목적: 본 연구는 BS 프리즘의 반사면을 이용한 주야 조준경의 개발에 관한 것이다. 방법: BS(beam splitting) 프리즘의 반사면의 상하에 도트시표발생부와 LCD 패널을 배치하고, BS 프리즘 전방에는 doublet 형태로 설계된 반사경을 배치하였다. 이렇게 함으로서 도트시표 발생부에서의 도트시표 허상을 관찰자 쪽에 결상시키도록 하는 기능, 외부 목표물 주변부의 정보는 관찰자에게 1배로 보이도록 하는 기능과 LCD 패널의 영상을 직접 관찰자가 볼 수 있게 하는 기능을 가진 새로운 형태의 BS 프리즘을 이용한 주야 조준경을 개발하였다. 결과: BS 프리즘의 반사면이 도트 시표를 반사시키는 도트사이트로서의 역할과 LCD 패널에 디스플레이된 야간 열영상을 관찰자가 관찰할 수 있도록 하는 반사 광학계 역할을 하도록 함으로써 주간에는 도트사이트로서 주간조준경 기능을, 야간에는 열영상 디스플레이 장치로서 야간조준경 기능을 하는 주야 조준경 장치를 개발하였다. 결론: 본 연구에서 우리는 기존의 도트사이트와 기존의 야간조준경을 BS 프리즘을 이용하여 결합함으로서 선택적으로 주야 조준경 역할을 할 수 있는 주야 조준경을 개발하였다. 이렇게 함으로써 우리는 기존의 도트사이트와 야간조준경의 착탈식 조합보다 사격의 신속성을 더욱 높일 수 있으며 총기류에의 장착에 있어서 보다 편리함을 제공해주는 새로운 형태의 BS 프리즘을 이용한 주야 조준경을 설계 개발할 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1656-1659
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• 2008

The reflective type color filter for the liquid crystal displays (LCD) was produced using cholesteric liquid crystal monomers whose phase is characterized by the unique optical features of selective reflection. Periodic micrometer scale hemi-spherical photoresist (PR) patterns were formed on glass substrates by thermal reflow method after photolithography. Cholesteric color filter films for red, green and blue light reflections were then produced and the viewing angle dependence was investigated and compared with that of reflected light on the non-patterned substrates.

• 한국전기전자재료학회논문지
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• 제16권6호
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• pp.501-509
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• 2003

We have designed transflective liquid crystal display(LCD) associated with in-plane switching of a LC director driven by fringe-field, unlike other LCD mode. Reflective area consists of a λ/2 compensation film and a LC cell with retardation value(dΔn) of λ/4 with their optic axes making an angle of 15$^{\circ}$ and 75$^{\circ}$ against polarizer, respectively. In the transmissive area, top and bottom polarizers are parallel each other, an LC has a dΔn of λ/2, and another λ/2 compensation film is inserted between the LC cell and bottom polarizer. With the configuration, both devices show dark state initially. When an incident light is 550nm, the device shows wide-viewing-angle characteristics such that in the reflective area the contrast ratio target than 5 exists up to 55$^{\circ}$ of polar angle in all directions and in transmissive area it exists about 100$^{\circ}$ in vortical direction and 110$^{\circ}$ in horizontal direction.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.972-975
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• 2003

We have performed computer simulation to obtain electro-optic characteristics of reflective hybrid aligned nematic liquid crystal displays driven by fringe field. The results show that the optimal retardation value of the cell is $0.289{\mu}m$, which allows for the cell to have a practical cell gap of larger than $3{\mu}m$ when manufacturing. A reflectance of the dark state is only 0.114% for an incident light 550nm. At this condition, the light efficiency of white state reaches 92.7%. Further, we have studied a new reflective display with polarizer, optical compensation with half plate, LC plus reflector. The display with optimized cell parameters shows low wavelength dispersion and the contrast ratio greater than 5 over exists about $120^{\circ}$ in vertical direction and $160^{\circ}$ in horizontal direction.