PSYCHOPHYSICAL APPROACH FOR EVALUATION OF OLED PANEL PERFORMANCE (OP13, 67-72)

OLED is expected as one of the next generation lighting devices. As OLED panel is a planar surface-emitting lighting device, non-uniformity of OLED due to several production process and non-uniform current density is easily detected. Therefore, luminance uniformity inside the panel, and the angular dependent uniformity in chromaticity are both important aspects in assessing the performance of the OLED panel. We tried to find an evaluation index to assess the uniformity of the OLED panel based on human perception. We simulated several non-uniform patterns on a LCD monitor, asking subjects to evaluate the non-uniformity of the stimulus, and tried to find the threshold for the detection of the non-uniformity. Our results showed that the uniformity perception in luminance distribution was affected by the gradient patterns. In addition, patterns whose central area was brighter than its peripheral appeared more uniform. Our findings suggest that it is necessary to consider complexity of gradient pattern and the form of luminance distribution to make an evaluating model for uniformity perception.