• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1419-1421
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• 2007

Color conversion technology using unique color conversion film for OLED back light was developed to achieve renovative performance for high- end display. It can reduce the production cost more than 20% due to cheaper cost for blue OLED and conversion film and also has a free chromaticity control capability for 10% raising color gamut with respect to LCD color filter. The OLED BLU by color conversion technology also shows excellent performances such as chromaticity stability. White efficiency using PLF + Blue OLED is 17cd/A@4.4V, CIExy(0.29, 0.31).

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.70-71
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• 2004

Back light unit(BLU) using a microlens fabricated by the modified LIGA process for the liquid crystal display(LCD) is proposed, and some experimental results are presented. To realize the back light unit using microlens pattern, LIGA and reflow process are used.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.213-216
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• 2007

LGP (light guide plate) of LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of the major components which affects the product quality of LCD. In the present study, the optical patterns of LGP(2.2") are manufactured by three different methods, namely, laser ablation, chemical etching and LiGA - reflow, respectively. The pattern surface images and roughness of mold and product were compared to check the optical characteristics. From the results of measurement the optical patterns fabricated by LiGA - reflow method showed the best geometric structure as intended in design and the lowest roughness among those.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.04a
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• pp.73-77
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• 2003

The backlight unit(BLU) is used as a light source of TFT liquid-crystalline-display (TFT-LCD) module. In this backlight unit, one of important components is the light guide, which is usually made of transparent polymers. Currently the screen-printing method is mainly used for the light guide as a manufacturing process. However, it has limitation to the flexibility of three-dimensional optical design. In the present paper a new alternative manufacturing method for the light guide with low-cost is proposed. This manufacturing method is named as direct surface forming (DSF), which is very similar to the well-known hot embossing except for partial contact between mold and substrate. The results of this new manufacturing method are presented in terms of processing condition, dimensional accuracy, productivity, etc.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.6 no.2
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• pp.76-80
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• 2013

In this paper, a external electrode fluorescent lamp driving inverter for LCD backlight is designed. AC input from a lamp-driven system to process up to two inverter system for the existing configuration of power-efficient than the system as well as to increase the volume and weight reduction, Furthermore low-cost advantage. AC power input in order to drive EEFL stable and AC 85V ~ 265V power factor increase in the PFC Block can be used for running the Inverter Block EEFL and composed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.7
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• pp.1275-1281
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• 2007

The discharge phenomena in a flat fluorescent lamp for the backlight unit of liquid crystal displays are simulated by sung a two-dimensional fluid model. The numerical methods for the calculation of plasma dynamics and the radiation transport are introduced for the discharge simulation and for the transmission of the vacuum ultraviolet lights. The simulation results are presented to compare the luminance and the luminance efficacy with the variation of gas pressure, gas mixture ratio, driving voltage, and frequency.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.241-244
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• 2004

Microlens patterned micro-mold fabrication method for Light Guiding Plate(LGP), kernel part of LCD-BLU(Back Light Unit), was presented. Instead of erosion dot pattern for LCP optical design, microlens pattern, fabricated by LIGA-reflow process, was applied. Optical pattern design method was also developed not only for negative pattern LGP, but also positive pattern LGP. In order to achieve flow balance during the micro-injection molding process and dimensional accuracy, two LGP pattern was made in one micro-mold.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1086-1089
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• 2006

We have developed 2.4" QVGA wide color gamut LCD module using RGB-LED backlight. The color gamut is achieved 100% of NTSC compared to 70% of NTSC when used with White-LED backlight. But RGB LED backlight is difficult to maintain its color balance since RGB LED is gradually degraded by the change of ambient temperature and a long term aging characteristic, etc. This paper describes a feasibility study of our optical feedback system developed for preventing such a color shift.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1530-1533
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• 2005

We investigated under-gate type carbon nanotube field emitter arrays (FEAs) for back light unit (BLU) in liquid crystal display (LCD). Gate oxide was formed by wet etching of ITO coated glass substrate instead of depositing $SiO_2$ on the glass substrate. Wet etching is easer and simpler than depositing and etching of thick gate oxide to isolate the gate metal from cathode electrode in triode. Field emission characteristic s of triode structure were measured. The maximum current density of 92.5 ${\mu}A/cm^2$ was when the gate and anode voltage was 95 and 2500 V, respectively at the anode-cathode spacing of 1500 ${\mu}m$.

• Journal of the Optical Society of Korea
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• v.13 no.2
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• pp.256-260
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• 2009

The optical performance of the reflective polarizer was investigated over three kinds of direct-lit backlights and/or different configurations of the optical sheets. The optical gain factor achieved by using the reflective polarizer increased as the diffuse nature of the optical sheet was enhanced, because of the more efficient polarization conversion. In addition, the gain factor decreased substantially in flat-lamp backlights compared to tubular-lamp backlights, which was ascribed to the high loss factor during the polarization recycling process due to the complex structure and large area of flat lamps. All these results suggested that reducing the loss factor of the backlight is very important for efficient polarization conversion and thus high optical gain of the reflective polarizer.