• Journal of the Optical Society of Korea
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• 제18권6호
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• pp.783-787
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• 2014

This paper presents an improved vertical alignment nematic liquid crystal mode characterized by the protrusions or slits of the top substrate and additional stripe type common electrodes with polarity switching of the bottom substrate to improve multi-domain vertically aligned (MVA) and patterned vertically aligned (PVA) nematic modes. MVA and PVA modes have disadvantages such as an LC disclination in the vicinity of the middle region of electrodes between the top and bottom protrusions in MVA mode or the top and bottom slits in PVA mode. Therefore, the stripe type common electrode generating a horizontal electric field and the protrusion or slit producing some pretilt of liquid crystals (LCs) were used to improve the LC disclination, which influences the transmittance and response speed. The simulation results showed that the proposed VA mode has higher transmittance than the MVA and PVA modes. As a result, the proposed VA mode can improve the response speed and transmittance remarkably, which makes it useful for upgrading the LCD display quality.

• Journal of the Optical Society of Korea
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• 제18권1호
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• pp.78-81
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• 2014

This paper presents an advanced patterned vertical aligned nematic liquid crystal (APVA) mode as a way of improving the transmittance of the conventional patterned, vertically-aligned nematic liquid crystal (PVA) mode. The APVA was characterized by multi-electrodes, which play an important role in generating a horizontal electric field that prevents LC disclination in the vicinity of the middle region of electrodes between top and bottom slits in PVA mode. The proposed APVA mode focused on improving dramatically the transmittance with excellent image quality. In the simulation, the APVA mode improved the transmittance by more than 22%, compared to the conventional VA modes. Therefore, it is useful to upgrade the LCD display quality.

• Steel and Composite Structures
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• 제37권5호
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• pp.551-569
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• 2020

Vibration of vertically aligned-monolayered-nonuniform nanorods consist of functionally graded materials with elastic supports has not been investigated yet. To fill this gap, the problem is examined using the elasticity theories of Eringen and Gurtin-Murdoch. The geometrical and mechanical properties of the surface layer and the bulk are allowed to vary arbitrarily across the length. The nonlocal-surface energy-based governing equations are established using differential-type and integro-type formulations, and solved by employing the Galerkin method by exploiting admissible modes approach and element-free Galerkin (EFG). Through various comparison studies, the effectiveness of the EFG in capturing both nonlocal-differential/integro-based frequencies is proved. A constructive parametric study is also conducted, and the roles of nanorods' diameter, length, stiffness of both inter-rod's elastic layer and elastic supports, power-law index of both constituent materials and geometry, nonlocal and surface effects on the dominant frequencies are revealed.

• Journal of Information Display
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• 제11권4호
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• pp.144-148
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• 2010

In this paper, vertically aligned (VA) liquid crystal (LC) modes were investigated using the alkyl chain ordering effect of self-assembled monolayers (SAMs) prepared on the anisotropic inorganic surface. On the anisotropic surface prepared through oblique ion beam irradiations, the SAM molecules are adsorbed, producing macroscopic alkyl chain ordering, which can determine the pretilt direction of the vertically aligned LC molecules through the intermolecular interactions on the surface.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.921-923
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• 2002

Vertically Aligned (VA) technology is an advanced technology for TFT-LCDs, which is mainly used in larger size displays like monitors for desktop computers and even for TVs. We will review our recent developments of Liquid Crystal (LC) mixtures for VA display modes.

• 한국전기전자재료학회논문지
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• 제21권3호
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• pp.260-264
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• 2008

We analyzed the lowering of transmittance due to lateral field effect in the edge of pixel. We studied the method to solve the problem of VA-LCD. It occurred director distortion and transmittance lowering by strong lateral field in the edge of pixel. For analyzing the director distortion and improving the transmittance lowering, we applied the edge pattern to PVA-LCD of cross pattern. As a results, transmittance in the new VA modes were higher than that of conventional VA modes.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.306-309
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• 2008

We proposed azimuthally continuous nematic domain mode characterized by a cone field induced from patterned electrode structure with a circular slit. This mode has good optical performances such as higher transmittance and wider viewing angle through decreasing the demerits caused by domain walls. We could confirm to these optical characteristics by the manufactured sample.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.186-186
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• 2009

Most liquid crystal display modes, including the twisted nematic (TN) $mode^1$, the in-plane switching (IPS) $mode^2$, the fringe field switching (FFS) $mode^3$, and the vertically aligned (VA) $mode^4$ are based on either a horizontal or a vertical alignment. However, for some applications, such as no-bias-bend (NBB) pi cell or bistable bend-splay display, an intermediate pretilt angle is essential$^5$. NBB pi cells have been a focus of interest because of their fast response time; however, the reliable control of the intermediate pretilt angle of liquid crystals that is required for the fabrication of NBB pi cells is challenging. The controllable pre-tilt angle of liquid crystals was investigated using a blend of horizontal and vertical polyimide prepared by a rubbing method. Various pretilt angles in the range from 0^{\circ}$ to 90^{\circ}$ were achieved as a function of the vertical polyimide content. We observed uniform liquid crystal alignment on the rubbing-treated blended polyimide layer. A NBB pi cell with an intermediate pretilt angle of 47.8^{\circ}$ was manufactured. This cell had no initial bias voltage and a low threshold voltage, which indicates that it has low power consumption. In addition, the response time of the NBB pi cell was rapid.