• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1642-1645
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• 2007

The brightness of LED changes according to the current flowing through LEDs. The current mirror was used to drive LEDs effectively. The reference current of the current mirror was usually controlled by the resistor but the size of this resistor is very large and this resistor consumes too much power for high power LED backlight driving. The reference current of the current mirror LED driver was controlled by using flyback converter at small size with low power consumption in this paper. The concept of active current source was presented.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1193-1195
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• 2008

We propose a novel light guide plate for an edge-lit LED backlight. Properly designed micro-prisms enable light to go out of the LGP in near vertical direction and luminance fluctuations in front of the LEDs to be invisible.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.214-217
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• 2008

We present an ultra-slim LCD module for 40-inch FHD TV. By employing edge-lit backlight system, module thickness of 10mm is achieved. To satisfy the luminance spec of 450 nits in FHD resolution, it is critical to adopt high efficient LED and optical components.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1503-1506
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• 2008

A novel white-LED (light emitting diode) backlight system for 46"LCD TVs which involves the current controlled X-Y channel driving method is proposed in this paper. There are two problems related to the LED current in the conventional X-Y channel driving driven by a constant voltage source. To solve these problems, a real time current sensing system is applied to the conventional one and the time-division current sensing method is employed.

• 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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• 2006.08a
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• pp.1729-1732
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• 2006

We proposed a new Mercury-free Flat Fluorescent Lamp (MFFL) for LCD backlight which shows a wide, stable operating voltage margin, high luminance and efficiency. In this paper, we expanded the single cell with 4 inch diagonal size into the multi-cell for the large size LCD-TV backlight application, examined its operating characteristics and proposed a driving scheme for 2-bit areal selective dimming control.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1157-1160
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• 2005

In order to improve the image quality of a large size LCD-TV, the Area-Focused Luminance Control (AFLC) technology with data processing algorithm has been developed. The AFLC backlight consists of 16 U-shaped lamps, and controllable areas are divided into 8 blocks. Based on the AFLC technology, the backlight luminance of each block is automatically and separately controllable. Consequently, the contrast ratio is greatly enhanced whereas the corresponding power consumption is decreased as compared with those of conventional backlights.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1507-1509
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• 2005

LCD(Liquid Crystal Display) products is needed to have high reliability and are produced without harmful material. Because Substitution for CCFL of Light source used to Conventional backlight unit, research is going about product with LED of light source at present. In this experiment, We made the LED backlight unit with high quality for automotivenavigation. This backlight unit has center luminance of 6500 nit at15W power consumption. We adjusted chromaticity by using ten Blue LED and eight side emitting type White LEDs with high power LED from Lumileds company.

• 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.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.235-238
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• 2006

As the screen size of LCD TV increases, an external electrode fluorescent lamp (EEFL) has been suggested to be applicable as backlight source for LCD TV. Since the EEFL has non-linear characteristics, which makes the analysis and design complicated. In this paper, the characteristics of the EEFL are investigated and a full-bridge RLC series-resonant inverter is analyzed and designed for EEFL backlight of 32-inch LCD TV. Finally, the experimental results are shown to validate the analysis and design.