[Paper] Spatial Uniformity Improvement at Low Luminance Levels for Organic Light-Emitting Diode Displays

Abstract

This paper proposes two methods for improving uniformity in the low luminance region of an organic light-emitting diode (OLED) display. To supply a stable current to subpixels in the low luminance region, the time-division method produces long-term and short-term subframes for the frame period. On the other hand, the area-division method produces non-emitting and amplified emitting regions of grouped pixels. These methods assume that the effective use of a high current improves spatial uniformity, as it becomes worse in low luminance regions. In experiments involving an actual display, the spatial distribution of luminance was measured while applying each of the proposed methods and evaluated based on the root mean square (RMS) value of the luminous deviation. When the results of the experiments with or without application of the proposed methods were compared, the proposed methods were shown to produce a decrease in the RMS value.