• Journal of Information Display
• /
• v.7 no.1
• /
• pp.19-24
• /
• 2006

We propose optical configurations of a double-cellgap liquid crystal cell for transflective displays with wide viewing angle and high contrast ratio. The reflective part is designed in the wide-band quarter wave structure to achieve good dark state. For the transmissive part, the compensation method is applied to achieve the super-achromatic dark state, and three switching methods are used : which are vertical switching, horizontal switching to $30^{\circ}$and horizontal switching to $120^{\circ}$, to achieve the bright state.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.498-501
• /
• 2009

Electrophoretic displays (EPDs) are attracting considerable attentions as a paper-like display. Especially, Electrophoretic cell consists of micron-sized, charged particles dispersed in a viscous fluid. When an external electric field is applied, the charged particles move with a speed proportional to the particle mobility and the local field strength. In electrophoretic displays fast switching times are required, so knowing the particle mobility is very important. In this paper, we study a novel simulation for calculating the particle motions submerged in a viscous fluid for horizontal switching electrophoretic cell.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.895-898
• /
• 2004

We propose configurations for a transflective in-plane switching (IPS) cell using muti-domain structures. Usually, the cell configurations for a transflective liquid crystal(LC) cell have a complicated structure, because retardation change of transmissive part and reflective part are not same. The transflective LC cell should have two configurations for each part, such as a multi-cell gap structure. With the ion-beam alignment and the horizontal switching LC cell, a simple structure for a transflective LC cell is proposed. The configuration only adopts one cell gap structure, which may help the enhancement of a yield. Their original optical properties in conventional transmissive and reflective type IPS liquid crystal dispaly(LCD) are kept, it shows the wide-viewing angle and the good wavelength dispersion characteristics.

• Proceedings of the Optical Society of Korea Conference
• /
• 2009.10a
• /
• pp.276-277
• /
• 2009

• Journal of Information Display
• /
• v.7 no.1
• /
• pp.12-18
• /
• 2006

We investigated the horizontal alignment properties such as surface morphology, pretilt angle, and polar and azimuthal anchoring energy of organic alignment material-coated surface treated by ion beam. In this investigation the energy and incident angle of ion beam were changed. We also fabricated an in-plane switching (IPS) cell by ion beam alignment. The results showed similar voltage-transmittance characteristics to those of a rubbed cell and better dark state.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.502-504
• /
• 2009

We demonstrate a pixel-isolated bistable twist-splay namatic (PI-BTSN) liquid crystal (LC) cell which has two stable states of splay and ${\pi}$-twist. Each state is stabilized by a multi-dimensional anchoring effect of pixel-isolating polymer walls without any chiral additives. Polymer walls are formed around the pixel region by anisotropic phase separation between LCs and reactive mesogens. Switching between the two states is archived by using vertical and horizontal electric fields. The memory mode of the fabricated LC cell has shown infinity memory time.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.39 no.4
• /
• pp.10-18
• /
• 2002

This paper reports a methodology for calculating distribution of the director in an In-plane switching liquid crystal cell by a numerical technique. To calculate distribution of the director, we developed a three dimensional finite element method (FEM) and calculated the distribution of electric potential and electric field in the liquid crystal cell. We have considered the free-energy density composed of electric potential and strain energy in the bulk of liquid crystal cell and calculated the switching property of liquid crystal cell by the Ericksen-Leslie equation and the Laplace equation We generated 1,859 nodes and 8,640 elements for IPS mode cell with 24${\mu}{\textrm}{m}$$\times$12${\mu}{\textrm}{m}$$\times$4.5${\mu}{\textrm}{m}$ and performed transient analysis until 16ms. As a result, horizontal electric field occurred at cell region except liquid crystal region above electrodes and the disclination occured on electrodes.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.41 no.8
• /
• pp.59-65
• /
• 2004

In this paper, we propose Pseudo-TN IPS mde(Pseudo-Twisted Nematic In-Plane Switching mode) based on IT(In-plane switching Twisted nematic) mode that increase contrast ratio from improving optical characteristics and analyze the characteristics of Pseudo-TN IPS uude. Optical transmittance is 25% higher for the PTN-IPS mode than for the IT mode. Because aperture ratio of the PIN-IPS is increased. And the control of Liquid Crystal for adjusting optical transmittance is more easier than IT mode, because optical transmittance variation is linear with applying voltage. Contrast ratio is 8% lower for the PTN-IPS mode than for the IT mode in the horizontal direction. But, Contrast ratio is 20% higher for the PTN-IPS mode than for the IT mode in the vertical direction. It has also cell gap margin and many benefits of IT mode, this may be used very well in the future LC Cell design.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.11a
• /
• pp.186-186
• /
• 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.

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