Jeong Hyun Seo

Mechanism of high luminous efficient discharges with high pressure and high Xe-content in AC PDP

The mechanism of high luminous efficiency discharges with high Xe content in an AC plasma display panel was analyzed by computer simulation using a two-dimensional fluid model. The model has reproduced well the experimental results. The high luminous efficiency with high Xe content is attributed to high electron heating efficiency as well as high excitation efficiency by electron. The electron heating efficiency is increased with increasing the sustaining voltage under high Xe content and this phenomenon was analyzed by investigating the cathode sheath and secondary electron emission characteristics.

Vacuum ultraviolet emission characteristics from He–Ne–Xe gas discharge in an alternating current plasma display panel cell

We measured the time integrated vacuum ultraviolet (VUV) emission spectra of He–Ne–Xe gas mixture from a surface type alternating current (ac) plasma display panel cell. The measured emission lines are the resonance line (147 nm) from Xe*(1s4), the first continuum (150 nm) and the second continuum (173 nm) from Xe dimer excited states. The relative intensities of VUV spectral lines from Xe* and Xe2* are dependent on the He/Ne mixing ratio as well as the Xe partial and total pressure. The intensity of 147 nm VUV increases with the Ne content increase and Xe2* molecular emission increases with the He content increase. Infrared (IR) spectra and the time variation of VUV were measured to explain the reaction pathway and the effect of the mixing ratio of He/Ne on the spectral intensity. A detailed study for the decay time shows that the decay time of 147 nm has two time constants and the radiation of 150 and 173 nm results mainly from Xe*(1s5). The IR spectra shows that the contribution from Xe**(>6 s) to Xe*(...

Two-dimensional modeling of a surface type alternating current plasma display panel cell: discharge dynamics and address voltage effects

To improve the luminance and efficiency of an alternating current plasma display panel, the direct measurement of infrared and vacuum ultra violet (VUV) imaging is performed to study discharge dynamics. Images show two emission regions. One is the cathode glow and the other is the anode glow. In the course of discharge cycle, the cathode glow propagates toward the outer edge of the electrode, while the anode glow does not propagate. We developed a two-dimensional model to simulate the time evolution of the discharge dynamics. We learned from the modeling results that the dominant role for the propagation of the cathode glow is the ion transport and the electron transport for the anode glow. In addition, the effects of address voltage on the luminance and efficiency are investigated during the sustain period. When the address electrode is floating, VUV output is larger than that of biased conditions, but the efficiency decreases slightly. The comparison of 100 V with 0 V bias shows that biased voltage does not affect the luminance and efficiency at the steady state.

Characteristics of vacuum ultraviolet emission from a surface discharge type alternating current plasma display panel cell

We have measured the time variation of 147 nm vacuum ultraviolet (VUV) resonance emission as well as the continuum such as 152 and 173 nm VUV and the two-dimensional images of 147 nm VUV from the He–Xe discharge in a surface discharge type single alternating current (ac) plasma display panel (PDP) cell using an image intensified charge-coupled device camera. A detailed measurement of the resonance radiation exhibits a fast rising to its peak and decay with multiple time constants. The changes in decay time constants, relative intensities of resonance, and dimer radiation change with the total gas pressure as well as the Xe partial pressure implies that collisional excitation, deexcitation, and interlevel transition play important roles in determining the VUV emission characteristics. The two-dimensional images show that a weak, broad VUV emission comes out from the cathode area with a strong, narrow emission from the anode area. We have solved the He–Xe discharge reaction equations together with the two-d...

Spatio-temporal characteristics of infrared and vacuum ultraviolet emission from a surface discharge type AC plasma display panel cell with He-Xe and Ne-Xe gas mixture

The spatio-temporal variations of 147 nm, 173 nm, and infrared emission images were obtained from a surface discharge type AC plasma display panel (PDP) cell with the He-Xe and Ne-Xe mixture. The differences in 147 nm, 173 nm, and infrared emission characteristics between He-Xe and Ne-Xe gas mixture were observed and explained by the differences in the xenon ion mobility and dimer reaction coefficients in two cases.

Effects of pre-reset conditions on reset discharge from ramp reset waveforms in AC plasma display panel

The basic characteristics of reset discharges related to a wall voltage and a priming effect were investigated under a conventional ramp driving scheme. The reset discharges could be minimized by controlling the wall voltage which is determined by pre-reset conditions. Accordingly, the current study presents a simple pre-reset condition for minimizing the reset discharge. Essentially, it is not only to reduce the duration of reset discharges but also to reduce the intensity of light emissions when the wall voltage polarity is opposite to the external voltage polarity.

Influence of Ion Bombardment on Electron Emission of MgO Surface in AC Plasma Display Panel

The influence of ion bombardment during a sustain discharge on the electron emission of the MgO surface and related driving characteristics of an ac plasma display panel were examined using the cathodoluminescence technique and SIMS analysis. The experimental results showed that severe ion bombardment predominantly sputtered Mg species from the MgO surface, thereby lowering the intensity of the F+ center peak to 3.2 eV due to the elimination of the oxygen vacancy and finally increasing the formative address delay time (Tf) due to an aggravated electron emission capability. Meanwhile, severe ion bombardment also destroyed the shallow trap level, thereby lowering the intensity of the shallow peak to 1.85 eV and eventually increasing the statistical address delay time (Ts) due to a poor electron emission capability from the shallow level. Finally, the aggravated electron emission capability from the shallow level resulted in a reduced wall voltage variation during the address period.

Analysis of the address and sustain discharges in an AC PDP cell using three-dimensional simulation

In the usual two-dimensional (2-D) simulations for the analysis of the plasma discharge in a three-electrodes coplanar-type alternating current plasma display panel (AC PDP) cell, the address electrode is regarded as an infinite plane electrode and the existence of barrier ribs is ignored. We have developed a three-dimensional (3-D) fluid code for the analysis of the plasma discharge in an AC PDP cell, where the address electrode and the barrier ribs can be properly treated. Using this 3-D code, we investigated the dynamics of charged particles and excited species during the address and the sustain periods. Time evolution of the Xe**(/spl ges/6 p states) excited species density profile shows a rounded bright head due to the effect of barrier ribs, which is consistent with the infrared images observed using an image intensified charge coupled device. Sustain voltage ranges for the successful sustenance of display discharges after addressing were obtained using both the 2-D and 3-D simulations through the voltage transfer curve analysis. In addition, the UV luminance and the efficiency changes with the variation of sustain voltages were obtained and compared with those of 2-D simulation.

Case studies on temperature-dependent Characteristics in AC PDPs

The temperature-dependent characteristics of ac plasma display panels (PDPs) are investigated, based on various case studies using a conventional driving scheme with reset pulses. Though the main factor of the thermal effects is caused by strong sustain discharges, it is not only caused by the panel characteristics, but also by the temperature-dependent characteristics of the driving system. One important thermal effect is a decreased breakdown voltage due to an increase in the panel temperature. Therefore, these results may be helpful in solving image-sticking and temperature-related phenomena.

New driving method for gray scale expression in AC plasma display panel

In this paper, a new gray scale expression method that divides scan lines into multiple blocks is suggested. The proposed method can drive 16 sub-fields per 1 TV field in the panel with XGA (1366/spl times/768) resolution. Because reset pulse is applied every 2 sub-fields, both the contrast ratio and the dynamic voltage margin are sufficiently obtained in comparison with previous AWD (address while display) methods. In realizing 16 subfields, shortening the scan time in the erase address period was important. The X bias voltage in the erase address period affected the minimum address voltage but did not the delay time of address discharge. The delay time of address discharge was affected by the address voltage and the time interval between the last sustain discharge and the scanning time. We also evaluated the dynamic false contour. The new method shows an improved image quality in horizontal moving, but discontinuous lines were observed at the boundaries of each block in vertical moving.