• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.88-90
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• 2003

We reported an AC PDP structure with grooved front panel dielectric layer. The structure exhibits low breakdown voltage, better luminance, and better endurance to crosstalk in high Xe contents. It also shows less luminous efficacy then conventional structure because of the thinner dielectric layer, but we can apply the higher Xe contents to the grooved dielectric structure, which results in the higher luminous efficacy. We made experiments with the Xe contents from 4 to16% and total gas pressure from 400 to 600Torr. The grooved dielectric structure shows the improvement of 20% luminous efficacy and 17% luminance. The firing voltages lower about 40V at 600Torr and Xe 12, 16%. The discharge characteristics of grooved dielectric structure are verified also with 2D simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.12
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• pp.2441-2445
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• 2009

The effects of Si -doped MgO have been investigated in order to improve the material properties of the MgO protective layer in plasma display panels. A small amount of Si is added to the MgO pellet while the MgO layer is being deposited by using an electron-beam evaporation method. Both the surface characteristics of the protecting layer and the electro-optical properties of 4 in. test panels are investigated, such as XRD patterns, SEM images, firing and sustain voltages, secondary electron emission coefficient($\gamma$), luminance, luminous efficacy and lifetime. The firing and sustain voltage are minimized when Si concentration is 0.038%, where the luminance and luminous efficacy increase up to 17% and 26% compared with that of the pure MgO film, separately, and lifetime also shows good characteristics.

• Proceedings of the KIEE Conference
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• 2004.11a
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• pp.299-301
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• 2004

Inductively coupled plasma is commonly used for electrodeless lamp due to its ease of plasma generation. Optical characteristics significantly depend on the RF power and gas pressure of the plasma. This paper describes the measurement of luminous efficacy as a function of RF power and gas pressure with a goal of finding optimal operating conditions of the electrodeless lamp. The gas pressure was varied from 10 [mTorr] to 100 [mTorr] and the RF power was varied from 10 [W] to 120 [W]. It was found that the luminous flux tends to be decreased when argon pressure is increased, and the luminous flux is increased as RF fewer is increased. It was also found that the luminance efficacy is high when the argon pressure is low and when the RF power is low.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.9
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• pp.1-5
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• 2013

We developed high-efficient 6W-LED package with simple structure by applying Heat Slug and silicone-reflector. LED package was manufactured in $8.5{\times}8.5mm$ sized multi-chip structure having thickness of $500{\mu}m$ achieved by bonding silicon-reflector with prepreg on top of the plate after implementing the reflector placed on copper substrate Half Etching by thickness of $200{\mu}m$. The luminous flux, luminous efficacy, correlated color temperature, color rendering index and thermal resistance of developed LED was evaluated, and it verified the application of products by applying it to 120W-LED road luminaires through simulation. The luminous efficacy of LED package reached over 130lm/W, and it is possible to be manufactured into 120W-LED road luminaires using 18 packages. In addition, the simulation results showed average of horizontal illuminance and overall illuminance uniformity that is suitable for three-lane road.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.7-13
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• 2008

Through two-dimensional numerical simulations, we analyzed the effects of new cell structure for the luminous efficacy improvement in an ac plasma display panel. In the new structure with 5 electrodes, two auxiliary electrodes are arranged between X and Y electrodes with long gap. Through the application of adequate auxiliary pulse on the address electrode, the luminous efficacy in the new cell structure showed the improvement of 52[%] in comparison with that of conventional cell structure with short gap between X and Y electrodes. Consequently, as the short gap discharge between auxiliary electrodes decreases and the long gap discharge between X and Y electrodes increases, the result of VUV generation efficacy shows higher improvement. The reliability of simulation result could he confirmed by the experimental result in the test panel.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.159-163
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• 2004

We have introduced fourth generation PDPs last year. The performance of these PDPs is the highest level among TV displays. At the same time the power consumption of them has reached to the lowest level among FPDs (Flat Panel Displays). High panel luminous efficacy and low address power are necessary for the reduction of total power consumption. Following technologies have been developed and applied to the fourth generation PDPs. High panel luminous efficacy: T-shape electrode, waffle rib structure, high Xe content gas Low address power; CLEAR driving method, etc.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.57-60
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• 2008

Over 5lm/W white luminous efficacy was obtained by 11" color test panel with narrowed discharge electrodes combined with high Xe partial pressure. By using optical spectroscopic methods, it was suggested that the electron heating efficiency is the most significant to improve the plasma efficiency in our experimental conditions.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1547-1550
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• 2008

We are suggesting a new index to represent the performance of PDP, such as Specific Performance Index (SPI) that includes luminous efficacy and panel reflectance. High Xe gas mixture and low panel capacitance are well known as key factors to improve luminous efficacy of PDP [1]. However, higher driving voltage and longer discharge time lag is an obstacle when applying these technologies. Modified cell design, new materials and driving waveform enable us to overcome these obstacles. High efficient phosphor is also a key material to improve luminous efficacy. Phosphors coated with pigment are used to reduce panel reflectance. High performance 50-inch HD PDP with luminous efficacy of 2.3 lm/W has been developed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.5
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• pp.982-988
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• 2009

In a surface type ac PDP having $200{\mu}m$ gap between the surface electrodes, the luminous efficacy has a reciprocal dependence on the sustaining frequency. The discharge current flowing to the address electrodes are measured to investigate the phenomena and spectral intensity from visible light to infra red is measured to verify phosphor saturation with the frequency. Experiments show the discharge between the address and surface electrodes deteriorates the efficacy in high sustaining frequencies. Pulse width modulation is introduced to improve the efficacy. In optimum conditions, we obtained 1.99lm/w and 1.79lm/w at 200kHz and 250kHz, respectively.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1710-1712
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• 2003

This paper analyzes the effects of various operating voltages on the luminous efficacy of high flux RGB LEDs. At first, their equivalent diode model are established from measurements of the V-I characteristics. Operating voltages of three types are applied to a simple LED circuit: DC, square-wave, and full-wave-rectified sine wave. As the result, DC voltage driving gives the hightest efficiency, but invokes much greater variation in the luminous flux and more shift in the peak wavelength.