• Transactions on Electrical and Electronic Materials
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• v.11 no.3
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• pp.134-137
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• 2010

We have proposed a transflective liquid crystal display (LCD) driven by the fringe field using a liquid crystal (LC) with a negative dielectric anisotropy. The device used different twist angles of the liquid crystals (LC) in the transmissive (T) and the reflective (R) regions when voltage is applied. With the optimization of the pixel electrode width and the distance between them, the LC directors in the R- and T-regions can be rotated by about $22.5^{\circ}$ and $45^{\circ}$ on an average, respectively. As a result, a high image quality transflective LCD with a single gap, a single gamma, and a wide viewing angle characteristics in both the R- and T- regions can be realized.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.335-338
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• 2004

In this study has developed analysis system for automatic inspection of FPD(Flat Panel Display) characteristic, such as brightness, view angle, color ratio in the manufacturing process. Developed system consists of inspection-sensor part, acquiring a data by 3-CCD Color CCD camera and Inspection-stage part, driving a FPD holder to rotation and tilt direction. In experiment results, we could have ensured easily brightness distribution, available view angle, color reproduce and could expect to improve the quality, productivity, and yield.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.271-273
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• 2008

A novel white-LED (light emitting diode) backlight system for 46"LCD TVs which involves the average current controlled X-Y channel driving method is proposed, which is composed of 1 converter and row and column channel switches. In the conventional X-Y channel driving driven with a constant voltage source, the driving current of LED increases because the threshold voltage of LED decreases when LED temperature goes up. To maintain the luminance of backlight constant, the average current controlled X-Y channel driving will be employed. Finally the results are confirmed by experimental results.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1059-1062
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• 2006

We report synthesis and properties of new phenothiazyl polymer derivatives, Poly(10-octyl-10Hphenothiazine-3,7-diyl)(POP), Poly(2',3',6',7'-tertrakis-octyloxy-9-spirobifluorene-2,7-diyl) (PTOSF), and their random copolymers, Poly(10-octylphenothiazine-co-2',3',6',7'-tertrakis-octyloxy-9-spirobifluorene) (POTOSF). PL emission of POP, PTOSF and POTOSF copolymer were found to be 480, 434 and 484nm, respectively. EL emission peak of double-layer EL device of POTOSF was at 494nm (bluish green).

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.256-259
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• 2006

Comparison of one two-path single energy recovery circuit for plasma display panel (PDP) is shown in this paper. A single energy recovery circuit (SERC) is proposed to reduce cost for manufacturing PDP and there are two ways, one and two-path, in driving this circuit. Compared with one-path SERC, there are low power consumption, low surge current and high performance in two-path SERC. The results will be shown with 42-inch HD panel.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1813-1818
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• 2006

We demonstrate a new approach to form gradient hole injection layer (HIL) in organic light-emitting diodes (OLEDs). Single spincoating of hole-injecting conducting polymer compositions with a perfluorinated ionomer results in gradient workfunction through the layer by self-organization, which lead to remarkably efficient single layer polymer light-emitting diodes (PLEDs) (${\sim}21$ cd/A). The device lifetime was significantly improved (${\sim50$ times) compared with the conventional hole injection layer, poly(3,4-ethylenedioxy-thiophene)/polystyrene sulfonate. This solution processed HIL also produced dramatically enhanced luminous efficiency (${\sim}34$ cd/A) in vacuum- deposited green fluorescent OLEDs while the vacuum deposited HIL gave the luminous efficiency of ${\sim}23$ cd/A in the same device structure.

• Journal of IKEEE
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• v.14 no.1
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• pp.40-46
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• 2010

This paper describes a clock and data recovery (CDR) circuit that supports dual data rates of 2.7Gbps and 1.62Gbps for DisplayPort standard. The proposed CDR has a dual mode voltage-controlled oscillator (VCO) that changes the operating frequency with a "Mode" switch control. The chip has been implemented using $0.18{\mu}m$ CMOS process. Measured results show the circuit exhibits peak-to-peak jitters of 37ps(@2.7Gbps) and 27ps(@1.62Gbps) in the recovered data. The power dissipation is 80mW at 2.7Gbps rate from a 1.8V supply.

• 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.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1061-1064
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• 2009

Through dark injection space-charge-limited current (DI-SCLC) and trap-free SCLC measurements, it has been demonstrated that an indium tin oxide (ITO)/buckminsterfullerene ($C_{60}$) electrode can form a quasi-Ohmic contact with N, N'-bis (naphthalen-1-yl)-N, N'-bis(phenyl) benzidine (NPB). The DI-SCLC results show a clear peak current along with a shift of the peak position as the field intensity varies, implying an Ohmic (or quasi-Ohmic) contact. A theoretical simulation of the SCLC also shows that ITO/$C_{60}$ forms an Ohmic contact with NPB. The Ohmic contact makes it possible to estimate the NPB hole mobility through the use of both DI-SCLC and trap-free SCLC analysis. This also contributes to a reduction in power consumption.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.557-559
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• 2009

We attempted modulation of hydrogen dilution ratio to achieve both the minimal incubation layer and high deposition rate. The incubation layer thickness was estimated by transmission electron microscopy (TEM) and crystallization fraction was measured by Raman spectroscopy.