16 Gray-scale driving schema based on DC-balance principle of electrophoretic display

The display quality improvement of electrophoretic paper largely depends on the increase in the number of grayscale, but it will make drive mode design complicated. The inhibition of residual driving voltage also becomes more difficult. This paper presents a new 16 gray-scale driving schema based on the DC-balance principle, improve the display quality of electrophoretic display (EPD). The display process is divided into DC rebalance phase and gray-scale drive phase. For every gray-scale conversion, pixel units make the original gray scale reach the basic gray scale via extreme white stage in the DC rebalance phase. Then a new gray-scale image is driven to show in the gray-scale driving phase. During the two sequential gray-scale conversions, voltages in the drive phase of the i
^th
conversion and DC rebalance phase of the (i+1)
^th
conversion always maintain DC balance, namely overall time of applying positive voltage in these two phases is equal to the overall time of applying negative voltage. The experimental results show that the proposed approach can effectively avoid the damage of driving electrode and display medium caused by the residual voltage accumulation, thus significantly extend the service life of the display.