Application of dichroic mirror for improvement of luminance and luminous efficacy in an alternating current plasma display cell

An alternate application of dichroic mirror for the improvement of luminanc e and luminous efficacy in an ac plasma display panel (PDP) is suggested. S ince only part of the vacuum ultraviolet (VUV) generated in the PDP cell is used to excite the phosphor, we propose deploying a dichroic mirror that i ncreases luminance and efficiency by reflecting part of the VUV toward the phosphor. The optical constants of the dielectric layers of the dichroic mi rror and a protecting layer of a PDP were determined from the measurements of reflectance and transmittance of the corresponding films and they were u sed to design the dichroic mirror including the protecting layer. The 147 n m xenon resonance line is usually used to activate the phosphor in the PDP cell. Thus, we designed the dichroic mirror to have a high reflectance for the VUV centered around 147 mn and a high transmittance for the visible lig ht. We investigated the usefulness of the dichroic mirror by comparing the luminance and luminous efficacy of test panels with and without the dichroi c mirror and found it could increase the luminance by 20%-31% and the lumin ous efficacy by 25%-34%. (C) 2001 American Vacuum Society.