• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1118-1120
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• 2004

Various technologies for new reflective LCDs with high performance are reviewed in this paper. Among of them, reflective STN-LCDs with single polarizor, novel single polarizor reflective LCDs based upon R-IPS mode and VA(vertical aligned) mode reflective color TFT-LCDs are discussed comprehensively. In addition, some new technologies which are under developed for the moment are also introduced briefly, including single polorizor reflective AF-LCDs (Antiferroelectric LCD) and reflective LCDS with none polorizor. Finally, we research the method to optimize the reflective LCDs.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.101-104
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• 2007

We propose a novel optical configuration for transmissive and reflective mode in the IPS LC cell to improve the viewing angle characteristics in a diagonal direction. The optical design was performed on a Poincar$\dot{e}$ sphere. From the calculation, we confirmed that the proposed configuration provides excellent viewing angle characteristics.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.2
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• pp.131-137
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• 2003

We have performed computer simulation to obtain electro-optic chracteristics of reflective liquid crystal display (LCD) using wide viewing angle LC mode, fringe field switching(FFS). Unlike other reflective LCD modes, in the FFS mode, the LC director in plance so an application to reflective display consisted of polarizer, LC layer and reflector is possible. when an incident light is 550mm, the optimal cell retardation value is 0.1365${\mu}$m and the efficiency of reflectivity is high over 90% with very little wavelength dispersion. Further, we have studied a new reflective display with polarizer, optical compensation film with half plate, LC plus reflector. The display with optimized cell parameters shows high contrast ratio (CR) over 130 with high light efficiency over 90% at normal direction and the CR greater than 5 exists over 60$^{\circ}$ of polar angle in all directions.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.587-589
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• 2009

The mode (reflective and transmissive) switchable LCD has been developed by using a treated SR (Selective Reflector) polarizer. We believe that our approach will be a solution to overcome weak points for a reflective and transflective mode in a dark environment and a transmissive mode in a bright environment. Therefore, this can minimize power consumption, and also be easily fabricated in a current manufacturing process, ready for large sizes.

• Journal of Information Display
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• v.11 no.3
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• pp.119-122
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• 2010

This paper proposes a transflective liquid crystal display (LCD) in a whole-pixel switchable configuration with a high aperture ratio using an electrophoretic particle layer (EPL). The switchable transflective LCD consisted of the liquid crystal layer as a display unit, and the EPL as a switchable mirror. The switching of the EPL between the mirror for the reflective mode and the transparency for the transmissive mode was performed by controlling electrophoretic nanoparticles with an applied voltage in a three-electrode structure. The single pixel was used as the whole transmissive or reflective mode that corresponded to the switchable EPL mirror. Thus, a transflective LCD with a high aperture ratio was obtained.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.292-294
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• 2008

We have developed new reflective LCD for Mixed twist nematic LC mode with high quality image. We have found out an optimal twist angle of LC and optical film's axis by simulation. Also we measured electro-optic characteristics for new design panel. As a result, high reflectance and wide viewing angle characteristics were achieved.

• Journal of information and communication convergence engineering
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• v.17 no.3
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• pp.221-226
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• 2019

In this work, a transmitter/receiver front-end module (T/R FEM) with an automatic Tx/Rx switching scheme for a 2.4 GHz microwave power transfer is developed for a retro-reflective beamforming scheme. Recently, research on wireless power transfer techniques has moved to wireless charging systems for mobile devices. Retro-reflective beamforming is a good candidate for tracking the spatial position of a mobile device to be charged. In Tx mode, the T/R FEM generates a minimum of 1 W. It also comprises an amplitude and phase monitoring port for transmitting RF power. In Rx mode, it passes an Rx pilot signal from a mobile device to a digital baseband subsystem to recognize the position of the mobile device. The insertion loss of the Rx signal path is 4.5 dB. The Tx and Rx modes are automatically switched by detecting the Tx input power. This T/R FEM is a design example of T/R FEMs for wireless charging systems based on a retro-reflective beamforming scheme.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.5-6
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• 2000

Fringe-field switching (FFS) technology exhibiting a high image quality has been developed. In this paper, one pixel concept, manufacturing process, materials, and electro-optic characteristics of FFS mode comparing with conventional in-plane switching mode, and its possible application to reflective type will be discussed.

• Journal of Information Display
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• v.1 no.1
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• pp.9-13
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• 2000

In liquid crystal displays, the display mode that represents initial liquid crystal alignment and method of applying voltage, mainly determines the image quality of display. Recently we have developed the fringe-field switching (FFS) mode exhibiting high image quality. In this paper, a pixel concept, manufacturing process, materials, and electro-optic characteristics of the FFS mode comparing with conventional in-plane switching mode, and its possible application to reflective type are discussed.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.112-113
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• 2000

주변의 광원을 이용하는 단일 편광판 반사형 액정 표시장치는 전력 소모의 70%이상을 차지하는 배면조명이 필요 없으므로 가볍고 얇으며, 소비전력이 적고, 큰 반사효율을 얻을 수 있는 장점으로 인해 큰 주목을 받고 있다. 현재 단일 편광판 반사형 액정 표시장치는 reflective TN(RTN)$^{(1)}$ 과 mixed-mode TN(MTN)$^{(2)}$ 과 같은 TN액정 모드를 기본적으로 사용하고 있다. 하지만 TN액정 모드를 사용한 반사형 액정 표시장치는 좁은 시야각과 느린 응답 특성 등의 문제점이 있다. 이러한 문제점들을 해결하기 위해 reflective-optically compensated bend(R-OCB)$^{(3)}$ 및 reflective homeotropic TN mode$^{(4)}$ , 반사형 BTN$^{(5)}$ 등을 이용한 반사형 액정 표시장치 등이 보고된 바 있다. (중략)