• Title/Summary/Keyword: luminous efficiency

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Improvement of luminous efficiency through new cell structure and driving pulse

  • Ko, Sang-Woo;Yang, Sung-Soo;Kim, Hyun-Chul;Mukherjee, Sudeshna;Lee, Jae-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.714-717
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    • 2003
  • We have suggested several plasma display panel (PDP) cell structures for high luminance and low power consumption by our two-and three-dimensional fluid simulation codes. Generally, to improve luminous efficiency and discharge efficiency, it is known that it is lucrative to use long discharge path and to form low electric field. However, the problems are how to implement them effectively in the small PDP cell. Therefore, unlike conventional model, we suggest Front Three Electrodes (FTE) model. In this model, we tried to make long and V-shaped discharge path by geometry changes and driving pulse variations. Consequently, from our simulation results based on the model above, luminous efficiency has improved about 2.6 times.

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New PDP cell designs for high luminous efficiency and radiation transport model in PDP

  • Yang, Sung-Soo;Shin, Seung-Won;Kim, Hyun-Chul;Lee, Jae-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.590-593
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    • 2002
  • Using two- and three-dimensional fluid simulation codes, we have suggested several new plasma display panel (PDP) cell structures that have high luminous efficiency compared with conventional structure. To improve the luminance and discharge efficiency, we utilize long discharge path, lower electric field region, and reduction of power consumption by adding one auxiliary electrode or reducing the electrode area. Consequently, luminous efficiency increases about 1.8 times. Furthermore for the resonance radiation trapping effect in PDP system, we have described a self-consistent radiation transport model coupled with fluid simulation using modified Holstein's equation.

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The Optical Characteristics of 240 W High Power LED Fish Luring Lamp (240W급 고출력 LED 집어등의 광학적 특성)

  • Bae, Jae-Hyun;An, Heui-Chun;Kim, Sang-Woo
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.19 no.6
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    • pp.681-687
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    • 2013
  • This study analyzed characteristics of 240 W high power LED lamps by comparing with those of traditional metal halide lamps. In addition, it analyzed the propriety of LED lamps as a source of light, considering seawater transmission characteristics. When Applying white LED package with the color temperature color temperature of 6500K, a 240W-LED fishing lamp has a characteristics of the luminous angle to be expanded to ${\pm}45^{\circ}$, the illumination change was improved to 0.8, as well as the luminance efficiency was improved to 98.8lm/W. As results of comparison between one 1,500W-metal halide lamp and four 240W-LED lamp with considering a seawater transmission and a luminous efficiency of scotopic vision, the radiant flux of two lamps were almost equal level at 50m depth and the luminous flux was 5% higher LED lamp than metal-halide lamp even if only applying the luminous efficiency of scotopic vision. As the luminous flux of LED lmap was 14% higher than that of metal-halide lamp with applying the luminous efficiency of scotopic vision to radiant flux at 50m depth, so LED fishing lamp was verified to alternative possibility of metal-halide lamp.

Efficiency Improvement of OLEDs depending on the Thickness Variation of BCP (BCP 두께 변환에 따른 OLEDs의 효율 향상)

  • Kim, Weon-Jong;Lee, Young-Hwan;Park, Young-Ha;Kim, Tae-Wan;Hong, Jin-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.349-350
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    • 2008
  • In the structure of ITO/N,N'-diphenyl-N,N' bis (3-methylphenyl)-1,1'-biphenyl-4,4'-diamine(TPD) /2,9-Dimethy 1-4,7-diphenyl-1,10-phenanthroline (BCP)/tris (8-hydroxyquinoline)aluminum$(Alq_3)$/Al device, we studied the efficiency improvement of organic light-emitting diodes due to thickness variation of BCP materials used for a electron breaking layer. The thickness of TPD and $Alq_3$ was manufactured 40 nm, 60 nm, respectively under a base pressure of $5\times10^{-6}$Torr using a thermal evaporation. The TPD and $Alq_3$ layer were evaporated to be at a deposition rate of 2.0 A/s. The BCP was evaporated to be at a deposition of 1.0 A/s. When the thickness of BCP increased from 5 to 30 nm, we found that the luminous efficiency and the external quantum efficiency is superior to the others when the thickness of BCP is 20 nm. Compared to the ones from the devices made without BCP, the luminous efficiency and the external quantum efficiency was improved by 57 %, 70%, respectively.

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A Study on the Influence of Coaxial Parallel Magnetic Field upon Plasma Jet (Plasma Jet의 동축평행 자계에 의한 영향에 관한 연구 ( 1 ))

  • 전춘생
    • 전기의세계
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    • v.22 no.2
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    • pp.57-69
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    • 1973
  • The aim of this study was to investigate the behaviors of plasma jet under coaxial magnetic field in paralled with it for controlling optical characteristics and input power of plasma jet without impurity and instability of arc plasma column. Because the discharge characteristics of plasma jet were so distinctively different according to the existence or non-existence of magnetic field, the input power, luminous intensity of plasma jet and thermal efficiency were comparatively studied in respect of such variables as arc current, gap of electrode, quantity of argon flow, magnetic flux density, diameter and length of nozzle, with the use of several materials which were different in diameter and length of nozzel. The results were as follows; 1) The voltage tends to show a drooping characteristic at law current and then rises gradually. The luminous intensity of plasma jet increases exponentially with arc current. 2) Arc voltage increases and luminous intensity tends to decrease gradually as gap of electrode increases. 3) Arc voltage and luminous intensity tends to decrease gradually as gap of electrode increases. 3) Arc voltage and luminous intensity increase in accordance with the quantity of argon flow. 4) At first step, arc voltage increases to maximum value with the growth of flux density and then tends to show a gradual decrease. Luminous intensity decreases with the growth flux density. 5) Arc voltage decreases as the constriction length of nozzle increases, maximum decrease is shown at the constriction length of 20(mm) and it increases beyond that value. The luminous intensity decreases as the constriction length grows. 6) Arc voltage and luminous in tensity increase with the growth of diameters of nozzle. 7) Thermal efficiency has values between 50% and 75%, being influenced by arc current, the quantity of argon flow, flux density, the length of electrode gap and the constriction length of nozzle.

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Research and Development of High Luminous Efficacy Plasma Displays

  • Kosugi, Naoki;Akiyama, Toshiyuki;Kitagawa, Masatoshi;Shinodaq, Tsutae
    • 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.

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Enhancement of the luminous efficiency of organic light-emitting diodes utilizing a wide-bandgap impurity doped emitting layer

  • Choo, D.C.;Bang, H.S.;Kwack, B.C.;Kim, T.W.;Seo, J.H.;Kim, Y.K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1447-1450
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    • 2007
  • The electrical properties of organic lightemitting devices (OLEDs) with wide-bandgap impurity-doped emitting layers (EML) were investigated. While the luminous efficiency of OLEDs with a NPB or a DPVBi-doped $Alq_3$ EML did not vary significantly with the current density, that of the OLEDs with a BCP-doped $Alq_3$ EML changed dramatically.

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Improvements of the luminous efficiency of mercury-free fluorescent lamps via structural and complex gas mixture changes

  • Oh, Byung-Joo;Jung, Jae-Chul;Seo, In-Woo;Kim, Hyuk;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.809-812
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    • 2008
  • Structural parameter variation effects (changing the coplanar gap under different discharge dimensions) and use of complex gas mixtures (He, Ne, Ar and Xe) in mercury-free fluorescent lamps are studied in this paper. Pure Neon gas is the best buffer gas for obtaining high luminous efficiency in mercury-free fluorescent lamps. It is shown that with a shorter coplanar gap (30mm), a high luminous efficiency can be obtained at low operating voltage, as well as high luminance uniformity and stable discharge with a Ne-Xe 20% gas mixture.

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High luminous efficiency AC PDP with the auxiliary electrode

  • Lee, Jae-Hyun;Park, Sang-Dae;Shin, Bhum-Jae;Choi, Kyung-Cheol
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.101-104
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    • 2003
  • The real test panel with the $200{\mu}m$ discharge gap in a coplanar AC plasma display panel was investigated. The auxiliary electrode was placed between two sustain electrodes and used for providing wall charges and prime particle during sustain period. The luminous efficiency had the maximum value when the voltage of the auxiliary pulses was 20 ${\sim}$ 100[V]. The luminous efficiency of coplanar long-gap discharge with auxiliary electrode was 2.6 times as much as that of the conventional structure.

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Auxiliary Address Pulse Driving Scheme for Improving Luminance and Luminous Efficiency in 42-inch WVGA Plasma Display Panel

  • Park, Ki-Hyung;Lee, Eun-Cheol;Cho, Ki-Duck;Tae, Heung-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.329-332
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    • 2003
  • The effects of an auxiliary address pulse driving scheme, in which an auxiliary short pulse was applied to the address electrode during a sustain-period, was examined under the various image patterns of the 42-inch WVGA ac-PDP. When the auxiliary address pulse driving scheme was applied, the luminance of the red, green and blue cells were measured respectively. The luminance, luminous efficiency and current were measured under the full-white pattern of the 42-inch ac-PDP. As a result, the luminance of blue cell was improved approximately by 17 %, whereas the luminous efficiency of the full-white pattern was improved approximately by 34 % without a misfiring discharge in comparison with conventional driving scheme.

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