Dynamic Driver Supply Voltage Scaling for Organic Light Emitting Diode Displays

Organic light emitting diode (OLED) display is a self-illuminating device that is supposed to be more power efficient than liquid crystal display (LCD). However, OLED display panels consume as much power as LCD panels due to total internal reflection. As the power consumption of the OLED panel depends on the pixel colors, most of the earlier power saving methods alter the pixel colors. In practice, such OLED power saving techniques can hardly accommodate photo viewers and movie players. This paper introduces the first OLED power saving technique that dynamically changes the supply voltage of the panel. Reduced supply voltage results in both power saving and decreased pixel luminance, but model-based color correction restores the decreased luminance with minimum color distortion. This technique is similar to dynamic backlight scaling of LCDs but is based on the unique characteristics of the OLED drivers. We provide an online color compensation algorithm using the luminance histogram. Luminance quantization in the histogram also achieves resource minimization. We develop a prototype and demonstrate the proposed OLED dynamic voltage scaling (DVS). Experimental result shows that the proposed OLED DVS saves up to 74.7% of the display power for the still images and up to 35.9% for movie clips.