We have studied the effects of ternary gas mixtures of Xe͑10%͒-Kr͑20% and 40%͒-Ne on the luminous efficiency in ac plasma display panels. Spatiotemporal behaviors of near infrared ͑IR͒ emission was measured by an intensified charge-coupled device camera equipped with a narrow bandpass filter and absolute densities of excited Xe * and Kr * atoms in the lowest resonance ͑1s 4 ͒ and metastable ͑1s 5 ͒ levels were measured by a technique of microscopic laser absorption spectroscopy. We have found interesting features from both emission and absorption experiments, such as longer near-IR emission ͑0.3-0.4 s͒ and different temporal behaviors between the excited Kr * ͑1s 5 ͒ atoms and Xe * ͑1s 4 ,1s 5 ͒ atoms. We have also found that the order of magnitude of the peak density of excited Kr * ͑1s 5 ͒ atoms ͑ϳ10 12 cm −3 ͒ was ten times smaller than that of Xe * ͑1s 4 ,1s 5 ͒ atoms, and that their decay time was remarkably short ͑ϳ0.3 s͒. These results have then been compared with those for a binary gas mixture of Xe͑10%͒-Ne. At a certain range of the sustain voltage, the production rate of Xe * ͑1s 4 ,1s 5 ͒ atoms and the luminous efficiency have turned out to be slightly improved for the ternary gas mixtures, compared to the binary gas mixture.