• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1613-1617
• /
• 2006

The total light efficiencies of the novel 1.9" transflective tRGB-t/rW and tRGB-rW TFT LCDs are calculated and they are implemented by the traditional 7-mask ${\alpha}$-Si processing. Then, the two vehicles are turned on with the appropriate Sub-Pixel Rendering White (SPRW) algorithms, so they can exhibit the extra luminance without the original visual resolution loss. Their outstanding optical properties are approved by measuring the contrast ratio (C.R.) and the NTSC ratio. Because they utilize the light resource very effectively and efficiently, they are very suitable for the dark indoor and the bright outdoor environments.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1601-1604
• /
• 2006

A novel photo-alignment scheme using normally incident periodically intensity-modulated UV light has been developed and demonstrated to efficiently yield a stable pretilt angle of nematic liquid crystals by single exposure. The scheme, referred to as the "photo-rubbing", consists in unidirectional scan of the intensity-modulated UV light over the photo-alignment film, which causes asymmetrical photo-reactions in the film. We show here its successful application to multi-domain alignment processing. Thanks to the normal incidence, the photo-rubbing removes the instrumental disadvantages of the conventional oblique incidence technique, thereby providing a true practical solution for photo-alignment.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.56-57
• /
• 2003

Sequential lateral solidification has recently become an option for manufacturing LTPS TFT LCDs owing to the availability of production equipment. Compared to the currently established ELA crystallization method, it is characterized by its low running costs and the high quality microstructures that can be obtained. In this presentation, we will review the production-related developments as well as elaborate on recent research activities that deal with a number of crystallization schemes that can be beneficial for future active-matrix display products.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.1005-1008
• /
• 2003

We report a new FCOG (flip chip on glass) technique using solder bumps for display packaging applications. The In and Sn solder bumps of 40 ${\mu}m$ pitches were formed on Si and glass substrate. The In and Sn bumps were bonded at 125 at the pressure of 3 mN/bump. The metallurgical bonding was confirmed using cross-sectional SEM. The contact resistance of the solder joint was 65 $m{\Omega}$ which was much lower than that of the joint made using the conventional ACF bonding technique. We demonstrate that the new COG technique using solder bump to bump direct bonding can be applied to advanced LCDs that lead to require higher quality, better resolution, and lower power consumption.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.686-689
• /
• 2003

This paper describes two kind of new concept for low power consumption for small area TFT-LCDs. First, the proposed analog buffer could reduce the static current by adopting new scheme. Second, new data driver structure reduced DC power consumption by reducing the number of operational amplifier (op-amp). As simulation results of Hspice, the quiescent current of proposed analog buffer is less than $0.8{\mu}A$ and the DC power consumption is reduced about $40{\sim}50%$ compared with conventional ones.

• Journal of Information Display
• /
• v.12 no.4
• /
• pp.191-194
• /
• 2011

A symmetric-viewing inverse-twisted-nematic (ITN) liquid crystal display (LCD) with alternating alignment layers was developed using a stamping-assisted rubbing (SAR) technique. A patterned layer of a fluorinated acrylate polymer was transferred onto the first rubbed vertical-alignment layer prepared on a substrate by stamping. The fluorinated acrylate polymer provided a protective layer covering the first rubbed alignment layer during the second rubbing process, which promoted the vertical alignment of the LC molecules. The LC cell in the ITN geometry with two orthogonally rubbed alignment layers showed symmetric-viewing characteristics with fourfold symmetry. The SAR technique was shown to be a mask-free alignment method of producing multidomains for symmetric-viewing LCDs.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.6
• /
• pp.416-428
• /
• 1999

A user-interactive pixel design tool for high-quality TFT-LCDs is realized and used to explore the sensitivity of the various array and device parameters for optimizing pixel design. In this tool, the Thompson cable equation and gradual-channel approximation were used for the gate time delay and TFT current modeling respectively. With this tool, each capacitance element, and TFT and array dimensions can be optimized under given design specifications. The electrical characteristics such ascharging ratio, gate time delay, pixel voltage level-shift, and holding ratio can be analyzed. The sensitivity analysis of those design parameters were executed and presented.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.19 no.12
• /
• pp.1144-1148
• /
• 2006

We have investigated liquid crystal (LC) aligning capabilities and electro-optical (EO) characteristics of transparent electrodes as Al-doped ZnO (AZO) substituting indium tin oxide (ITO). The experiment results show that a uniform vertical LC alignment on AZO electrodes based on a rubbed polyimide (PI) surface were achieved. A high pretilt angle of about $88^{\circ}$ was obtained. EO performances of the VA cell on rubbed PI surfaces with AZO electrodes are almost the same as that of the VA cell with ITO electrodes. These results appeared that AZO electrodes as transparent electrodes of LCDs could substitute ITO electrodes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.14 no.7
• /
• pp.590-594
• /
• 2001

The residual DC properties in the in-plane switching (IPS) liquid crystal displays(LCDs) which have different concentrations of cynao NLCs and different resistivities of fluorine NLCs were studied. We also propose a new residual DC measurement method, named 'light minimum/maximum method'. We confirmed the precision of residual DC measurement by light minimum/maximum method compared with the flicker minimizing method and found that new measurement method of residual DC is more accurate than that of the conventional flicker minimizing method since the resolution level of measurements is in 0.1V.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.15 no.10
• /
• pp.902-908
• /
• 2002

Homogeneously aligned nematic liquid crystal displays (LCDs) driven by in-plane or fringe field were known to exhibit wide viewing angle and appeared to be black in the off state. However, the existence of spacers inside the cell causes the deformation of the liquid crystal molecules. Such a deformation of the liquid crystal causes light-leakage in the dark state, which lowers contrast ratio of the display. We found that the light-leakage due to deformation of the LC director near the spacer mainly depends on the dielectric anisotropy and the ratio of elastic constants of the LC. In this paper, the mechanism on deformation of the LC near spacer is investigated by optical polarizing microscopy.