• Journal of Information Display
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• v.4 no.3
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• pp.22-25
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• 2003

In this paper, we propose the bistability the bistability in a chiral-splay nematic liquid crystal cell, which is obtained by adding a chiral additive to a splay cell and introduce a novel switching method for the bistable chiral-splay nematic cell in order to transit the LC director between the non-twisted state with splay and the 180$^{\circ}$ twist state.

• Journal of Information Display
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• v.5 no.2
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• pp.19-22
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• 2004

A ${\pi}$ cell is initially in splay state. Before driving a ${\pi}$ cell, transition from splay to bend state is always necessary which originates from nucleation. We propose a novel technique to make bend transition fast and effectively by forming transition cores around the pixels with the technique of multi-domain alignment, where domain boundaries play a crucial role in splay to bend transition. This noble technique enables the splay to bend transition to occur within less than 2 seconds with a low applied voltage.

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.194-198
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• 1991

네마틱 액정셀에 사각전압펄스를 가하며 액정의 splay 변형시간을 조사하였다. 광학적 방법으로 복굴절 신호의 오름시간과 네팀시간을 측정하였으며 외부전압과 두께를 변화시키면서 신호 형태와 반응시간의 변화를 관찰하였다. 그 결과는 Leslie-Ericksen의 식으로 근사적으로 분석할 수 있으며 이로부터 점성 계수를 구할 수 있다.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.903-906
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• 2004

A ${\pi}$ cell is initially in splay state. Before driving a ${\pi}$ cell, transition from splay to bend state is always necessary which originates from nucleation. We propose a novel technique to make bend transition fast and effectively by forming transition cores around the pixels with the technique of multi-domain alignment, where domain boundaries play a crucial role in splay to bend transition. This noble technique enables the splay to bend transition to occur within less than 2 seconds with a low applied voltage.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.555-558
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• 2003

The bistability in a chiral-splay nematic liquid crystal cell, which is obtained by adding a chiral additive to a splay cell, is proposed. In this paper, we describe a new horizontal way of switching between the two states of the bistable chiral-splay cell, one state being characterized by a non-twisted director field with splay, the second state showing a director-field with $180^{\circ}C$ twist.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.433-436
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• 2002

Retardation liquid crystal films with a profiled titled optic axis (splay films) of both nematic and discotic types are used as compensation films for twisted nematic displays (TN-LCD). A new method is developed to characterize retardation vs. inclination (retardation profile) of splay films by three parameters: "full retardation" $d^{\ast}{\triangle}n$, "inplane retardation" $R_0$ and "retardation difference" $R_d$ . Splay films with the same retardation profile but with different tilt profile (retardation invariants) are discovered. Splay films with different structure parameters but belong to the same retardation invariant have the same compensation opportunities for TN-LCD.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.327-329
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• 2008

We have studied the optically compensated splay (OCS) mode using reactive mesogen monomer to reduce critical voltage, setting voltage and phase transition time from initial bend to splay state. The high pretilt angle from vertical alignment was formed through the polymerization of UV curable RM monomer at the surfaces. In this way, orientation of the LC with OCS can be achieved without setting voltage.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.9
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• pp.983-987
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• 2004

We have studied electro-optic characteristics of reflective optically compensated splay (R-OCS) cell. The initial configuration of this cell is in splay form such that a mid director lies parallel to the substrate and around it hybrid structure is formed symmetrically so the optically compensation effect exists. Optimized optical configurations could be achieved by using a single polarizer, a quarter-wave film and a cell with quarter-wane retardation. The optimal cell retardation is 0.34 ${\mu}$m, allowing to have large cell gap. The cell provides high contrast ratio of 80:1 at normal direction and the region with contrast ratio over 5:1 covert up to 160$^{\circ}$ horizontally and vertically at all wavelength range.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.5
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• pp.536-540
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• 2004

A novel nematic liquid crystal (LC) cell with splay structure exhibiting wide viewing angle, fast response time and high transmittance at the same time has been developed. With rubbed homeotropic alignment in parallel directions, the device shows bend alignment in the absence of vertical electric field. However, with applied high voltage in a pulse form, the LC shows a optically compensated splay (OCS) orientation such that the mid-director is parallel to a substrate and at both surfaces the LCs are aligned vertically in parallel direction. In the device, the birefringence of the cell becomes tunable with applying voltage, i.e., the amount of light passed through the cell can be controlled by controlling the orientation of the LC. Since the OCS cell has a self-compensation structure such that the LC has a mirror symmetry along the mid-director, the device shows a wide viewing angle with only a single domain and a fast response time.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.538-541
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• 2007

In this paper, with a bistable curve of the bistable chiral splay nematic liquid crystal (BCSN LC) device, we clarify how the twist-to-splay transition is achieved under a horizontal field. By a sufficiently high horizontal electric field, the bistable property becomes monostable. The transition can be achieved.