A Low-power Algorithm for Electrowetting Displays Based on Ambient Light Dynamic Compensation

Electrowetting Display （EWD）， as a novel reflective display technology， offers high reflectivity， wide viewing angles， fast response， and full-color display， making them highly promising for applications in portable terminals， wearable devices， and outdoor information displays. However， as display panels evolve toward larger sizes and higher resolutions， the scale of driving circuits and refresh rates increases significantly， leading to growing power consumption issues that directly affect device battery life and application scope. Existing low-power studies rarely fully integrate the reflective imaging characteristics and optoelectronic properties of EWD， and power optimization under complex ambient lighting conditions still has considerable room for improvement.To address these challenges， this paper proposes a low-power algorithm based on ambient light compensation， designed to reduce power consumption and improve display quality by leveraging the reflective characteristics of EWD. In addition， an adaptive voltage adjustment technique is introduced， which dynamically adjusts the driving voltage according to ambient light intensity， further reducing driving power consumption. The proposed low-power algorithm consists of four main components： 1） voltage–reflective luminance curve calibration， ensuring that the luminance differences between adjacent gray levels under various ambient light conditions are closer to those under standard ambient light； 2） extraction of the original grayscale information of the image， followed by grayscale correction using a mapping table generated during the calibration process； 3） detail enhancement to improve edge and texture representation in the image after calibration， compensating for potential detail loss； and 4） calculation of the driving voltage corresponding to the highest pixel value after processing， based on the Pulse Amplitude Modulation （PAM） driving method， and setting it as the maximum driving voltage for the given ambient light condition to achieve adaptive voltage adjustment.The proposed ambient light dynamic compensation calibration method was applied to an EWD system. Test points were set at the positive and negative power supply terminals of the source driver， and an EKA1080M power consumption tester was used to measure the power consumption before and after algorithm processing. The test video sequence consisted of black screen-original image-black screen-processed image-black screen， enabling comparison of power consumption differences before and after processing. Results show that， in the source driver voltage section， the processed images consumed significantly less power than the original images. Further measurements of current and voltage at the test points under different ambient light conditions， combined with the power calculation formula， revealed that the overall power consumption under standard ambient light was 18.93 mW/in²， and decreased to 14.21 mW/in²， 12.06 mW/in²， and 11.72 mW/in² under ambient light intensities of 483 cd/m²， 970 cd/m²， and 1 730 cd/m²， respectively—representing reductions of 24.9%， 36.3%， and 38.1% compared to the unoptimized case.In terms of image quality， the objective evaluation metric Average Gradient （AG） increased by 4.9%， 3.9%， and 2.3% under the three ambient light conditions， respectively， indicating that the processed images exhibited higher clarity， more prominent edges， and richer details. Moreover， the brightness of the processed images was closer to that of the standard ambient light display， providing a more comfortable and stable viewing experience under varying lighting conditions. In summary， the proposed method significantly reduces the power consumption of EWD while effectively maintaining and even enhancing display quality.