Design of Multi-DC Overdriving Waveform of Electrowetting Displays for Gray Scale Consistency

Abstract

Gray scale consistency in pixels was extremely important for electrowetting displays (EWDs). However, traditional electrowetting display driving waveforms could not obtain a pixel aperture ratio consistency, which led to the occurrence of gray inconsistency even if it was the same driving waveform. In addition, the oil backflow caused by charge trapping could not be sustained. Therefore, a multi-direct current (DC) overdriving waveform for gray scale consistency was proposed in this paper, which could effectively improve the performance of EWDs. The driving waveform was divided into a start-up driving phase and a stable driving phase. The stable driving phase was composed of a square wave with a duty cycle of 79% and a frequency of 43 Hz. Subsequently, an overdriving pulse was also introduced in the stable driving phase. The multi-DC driving waveform for gray scale consistency was applied to a thin film transistor-electrowetting display (TFT-EWD). The average difference between increasing driving voltage and decreasing driving voltage was only 2.79%. The proposed driving waveform has an aperture ratio of 3.7 times at low voltages compared to DC driving.

Qualitative Classification of Proximal Femoral Bone Using Geometric Features and Texture Analysis in Collected MRI Images for Bone Density Evaluation

“…Features such as the pixel gray-scale average (as an indicator of bone marrow fat and the BMD) [28], the fractal dimension (using the Boxing count method), and the gray-level co-occurrence matrix were also derived from texture analysis (for further information on the image segmentation and texture analysis refer to the work of Larroza et al [29]). A Then, statistical functions such as the minimum, maximum, mean, variance, elongation, skewness, and first and second moments of the signal (moment1 and moment2 in Table 1) of these descriptors were calculated.…”

“…Features such as the pixel gray-scale average (as an indicator of bone marrow fat and the BMD) [28], the fractal dimension (using the Boxing count method), and the gray-level co-occurrence matrix were also derived from texture analysis (for further information on the image segmentation and texture analysis refer to the work of Larroza et al [29]). A total of 68 primary features were extracted.…”

A Driving Waveform with a Narrow Falling and High-Voltage Reset Structure for Improving the Stability of Electrowetting Displays

“…However, it could not improve the charge-trapping problem in the insulating layer. Therefore, a dynamic adaptive display driving waveform based on a thin film transistor-electrowetting display (TFT-EWD) was proposed to solve the discontinuous static image display defect caused by charge capture [26]. The driving waveform used the DC hybrid driving model and the source non-polarized model (SNPM).…”