Influence of gas mixture ratio on the luminous efficiency in surface discharge alternating current plasma display panels New combination of a three-component gas, Ne-Xe-Ar, for a high efficiency plasma display panelThe dependence of the efficacy of an alternating current surface-discharge plasma display panel on the gas pressure is investigated for several Xe-Ne gas mixtures. In monochrome green 4 in. test panels the efficacy trends and emission spectra are examined for increasing gas pressure and/or Xe concentration. The measured panel efficacy and emission characteristics are compared with the results of a numerical discharge model. It is found that the discharge efficiency for the cell geometry used in present-day commercial products can be increased significantly by using a larger Xe partial pressure. An increase of the electron heating efficiency and of the Xe excitation efficiency contribute about equally to the efficacy increase. The contribution of the increasing Xe dimer radiation fraction to the efficacy improvement is relatively small. These findings are applied in a 4 in. color test display with a design that resembles the one used in present-day commercial products and contains a gas mixture of 13.5% Xe in Ne at 800 hPa. For realistic operating conditions an efficacy of 3.8 lm/W at a white luminance of 2010 cd/m 2 is obtained. Furthermore, the panel chromaticity improves for increasing Xe partial pressure due to decreasing Ne emission.

The dependence of the panel efficacy of an alternating current-surface-discharge plasma display on the input power is investigated. Test panels with a design resembling the one used in main stream commercial products are used. The input power is varied in two ways: namely by changing the dielectric layer capacitance (thickness) and by changing the sustain voltage. An interesting different behavior is found: for increasing capacitance the efficacy decreases markedly, whereas for increasing sustain voltage the efficacy increases slightly. The different behavior is attributed to changes in the ion heating losses. It is found that plasma saturation, which implies a fundamental trade-off between luminance and efficacy, is not significant at practical input power values. A high luminance and a high efficacy are concurrent for a plasma panel design with a low dielectric layer capacitance and a high sustain voltage.

The dependency of the efficacy of an alternating-current surface-discharge plasma-display panel (PDP) on the gas pressure was investigated for several Xe-Ne gas mixtures. Also, the sustain voltage was varied. Monochrome 4-in. test panels, with a design which resembles the one used in mainstream commercial products, were used. The experimental panel efficacy and emission characteristics were compared to the results of a numerical discharge model. A strong increase in the efficacy for increasing voltage was found in high-gas-pressure mixtures with a high Xe concentration. An increase in the electron-heating efficiency and of the Xe-excitation efficiency contribute, about equally, to the increase in efficacy. The increase in the Xe-excitation efficiency is due to an increase in the excitation in the lower Xe levels induced by a lowering of the electron temperature. The contribution of the increasing Xe-dimer radiation fraction to the efficacy improvement is relatively small. These results imply an efficient panel design comprised of the combination of a high Xe concentration, a high gas pressure, and a high sustain voltage. A high luminance and a high efficacy are concurrent for such a design. A 4-in. test panel containing a mixture of 13.5% Xe in Ne at 800 hPa has been realized, demonstrating a white luminance of 2600 cd/m 2 and an efficacy of 3.1 lm/W for continuous operation at 50 kHz and 230 V.

The dependence of PDP luminance and efficacy on the input power was investigated for several Xe-Ne gas mixtures. The input power was varied in two ways: namely, by changing the dielectric-layer capacitance (thickness) and by changing the sustain voltage. A distinctly different behavior was found; for increasing capacitance the efficacy decreases markedly, whereas for increasing sustain voltage the efficacy increases. A design window comprising the combination of a high Xe concentration and a high sustain voltage was suggested. In this window, a high luminance and a high efficacy are concurrent. A 4-in. test panel with 10% Xe in Ne has been realized showing a white luminance of 2040 cd/m 2 and an efficacy of 2.3 lm/W for continuous sustaining at 50 kHz with a sustain voltage of 225 V.

The performance of two 4-in. color PDP test panels with a default and a high-Xe-concentration gas mixture will be discussed. The default panel with a gas mixture of 3.5% Xe in Ne and a filling pressure of 665 hPa was compared with a panel containing a gas mixture of 13.5% Xe in Ne and a filling pressure of 800 hPa. The panels contain a green phosphor, YBO 3 :Tb, which showed less saturation at high UV load compared with a Willemite phosphor. The panel performance was compared in addressed conditions. For the default panel, a white luminance of 710 cd/m 2 and an efficacy of 1.6 lm/W was found, while for the high-Xe-partial-pressure panel, a white luminance of 2010 cd/m 2 and an efficacy of 3.8 lm/W was realized. The increase of the driving voltages, about 20-30 V, is moderate. Finally, color saturation is improved at high Xe partial pressure.