• Journal of Information Display
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• v.4 no.4
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• pp.19-24
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• 2003

By using vacuum in-line driving and photoluminescence measuring system, we have examined the electrical and optical characteristics of plasma display panel produced by vacuum in-line sealing technology. In addition, the relationship between luminous efficiency and base vacuum level before filling discharge gas was analyzed. In the case of base vacuum level of $1.33{\times}10^{-1}$ Pa, the firing voltage of a 2-inch diagonal PDP panel was ranged from 312 to 343 V depending on the discharge gas pressure of $2.667{\times}10^4$ to $4{\times}10^4$ Pa at room temperature, Whereas in the case of $1.33{\times}10^{-4}$ Pa, the firing voltage was reduced by 40 V and luminescence was improved slightly.

• Journal of Information Display
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• v.7 no.4
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• pp.1-4
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• 2006

The optical performances of rounded prism films were investigated using a ray tracing technique. The angular distribution of the luminous intensity was obtained as functions of the prism pitch and the curvature of rounded apex and valley of prism arrays. The gain of the on-axis luminance decreased with decreasing curvature (increasing diameter) and pitch. The existence of the curved area on the prism film decreased the recycling efficiency of the prism film, i.e., the rays which would otherwise have been recycled through total internal reflections via the prism surfaces were refracted on the curved regions and redirected toward directions other than the on-axis direction. Quantitative correlation between the luminance gain and the curvature in addition to the prism pitch was obtained, which might serve as basic data for the optimization of prism films and the manufacturing processes.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.784-787
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• 2008

Nanoscale $YVO_4:Eu^{3+}$ phosphor has been synthesized by a mild hydrothermal reaction at various experimental conditions. The particle and luminescent properties of nanophosphors were characterized with X-ray diffraction, electron microscopy and photoluminescence. It has been found that pH value play a key factor both controlling particle size and luminous efficiency.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.499-502
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• 2008

Effects of a dielectric capping layer on the luminous characteristics of top emitting organic light emitting diodes (TOLEDs) have been analyzed using a classical electromagnetic theory. Special attention was given to the influence of the cavity length on the effectiveness of the capping layer. The luminance characteristics of the TOLEDs influenced by the combined effects of the cavity length and the capping layer thickness. Furthermore, these combined effects also modify the emission spectrum and pattern of the TOLEDs, which result in the improvement of total luminance of the device, but no significant change in the device out-coupling efficiency.

• KIEAE Journal
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• v.2 no.2
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• pp.33-38
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• 2002

There are a number of practical uses for devices which are capable of piping large amounts of light: illumination of areas where there would be maintenance, safety, or security problems with electronic light sources; piping sunlight into indoor areas for illumination; and the conversion of high luminous efficacy, good color quality, high intensity discharge lamps into more acceptable linear of area sources of light. Prism light guides are hollow structures which pipe light by means of total internal reflectin(TIR). These devices are unique in their ability to combine the efficiency of TIR with the relatively low cost of hollow structure. An important application stems from their ability to transform a point source of light such as an incandescent or discharge lamp into a linear or area source of light or illumination. We report the development of an economical, flexible prismatic film for fabricating the light guide wall. This guide geometries and films are currently under development.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1067-1070
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• 2006

We have demonstrated highly efficient WOLED with two separated emissive layers using a blue fluorescent dye and a red phosphorescent dye. The maximum luminous efficiency of the device was 11.2 cd/A at $20\;mA/cm^2$ and $CIE_{x,y}$ coordinates varied from (x = 0.33, y = 0.37) at 6V to (x = 0.25, y = 0.33) at 14V.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.886-889
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• 2006

Twin Auxiliary Electrodes were applied to the counter sustain electrode structure plasma display panels for the improvement of luminous efficiency. In advanced, we investigated the spatiotemporal behaviors of excited $Xe^{\ast\ast}(2p)$ atoms in that structure unit cell with various applied voltage conditions for the auxiliary electrodes. The near-IR emissions were observed by an ICCD camera combined with narrow band pass filter. As a partial result, the intensity of IR emissions and the response time were improved with the proposed twin auxiliary electrodes.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.932-934
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• 2006

A relationship between discharge delay time and the aging method were investigated: A-Y (Address electrode - Scan electrode) aging and conventional X-Y(Common electrode - Scan electrode) aging with the variation of sustain voltage beyond self-erasing discharge. Although A-Y aging decreases discharge delay time, it has several drawbacks like non-uniformity of discharge, degradation of luminous efficiency and a color temperature. In a conventional aging condition which is carried out near the mid-margin voltage, discharge delay time is short in low voltage and high frequency condition. As an alternative to conventional voltage aging, high voltage aging is suggested which is carried out at self-erasing sustain voltage region. High voltage aging shows lower discharge delay time and fast aging speed than conventional voltage aging.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1050-1053
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• 2006

We fabricated white organic light emitting diodes consisting of three emitting layers of red-emitting DCM2 doped ${\alpha}-NPD$, blue-emitting DPVBi and green-emitting C545T doped Alq3. By optimizing the thickness of the hole-transport layer of ${\alpha}-NPD$ and the electron-transport layer of Alq3, efficient white OLEDs were obtained with a luminous efficiency of 4.40lm/W at luminance of $1000cd/m^2$, and a max-imum luminance of $51,939cd/m^2$

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.137-140
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• 2006

The prototype of the field emission display with carbon nanotube emitter is developed in this study. To improve the brightness and color gamut of the prototype, new phosphor material, $SrGa_2S_4:Eu$, is adopted instead of conventional CRT-green phosphor. By replacing the green phosphor, the prototype shows significant improvements in the brightness and color gamut. At the anode voltage of 7 kV and the anode current of $2{\sim}3\;{\mu}A/cm^2$ the brightness is higher than $600\;cd/m^2$. The luminous efficiency of the prototype is about 7.7 lm/Watt.