Maintaining DC balance in electronic paper displays using contrast correction

摘要

Systems and methods for maintaining DC balance in bi-stable displays using contrast correction are disclosed. The system includes a DC balance module and storage for DC corrective waveforms. The DC balance module generates transitional driving schemes which drive pixels to new color values while simultaneously shifting each pixel's relative impulse potential values to be in line with those of the new speed drive scheme. The transitional driving schemes ensure DC balance by performing contrast and color-depth correction. In particular, the transitional driving schemes lower the contrast and reduce the color depth of pixels when increasing the speed of page flipping and raise the contrast and color depth when reducing the speed of page flipping. The present embodiment of the invention also includes a method for variable-speed page flipping with contrast correction and a method for creating a transitional driving scheme.

主权项

1. A method comprising:
driving an electronic paper display with a first pixel driving scheme having a first rate of page transition; determining a second driving scheme having a second rate of page transition; in response to determining that the rate of page transition is varying from the rate to the second rate, determining a transitional pixel driving scheme, including a drive waveform and a contrast correction waveform, by:
selecting a waveform length for the transitional pixel driving scheme, wherein the waveform length for the transitional pixel driving scheme is equal in length to a longer waveform length of the first and second pixel driving schemes;using a shorter waveform of the first and second pixel driving schemes for the drive waveform;inserting the drive waveform into a first portion of the transitional pixel driving scheme;selecting a pixel color to remain fixed based in part on determining that the pixel color is associated with a largest amount of pixels in both a previous image and a desired image during a page transition;determining, for the first pixel driving scheme and the second pixel driving scheme, relative impulse potentials of each nominal color relative to the fixed color;subtracting the relative impulse potential of the first pixel driving scheme from the relative impulse potential of the second pixel driving scheme to determine an impulse potential for the contrast correction waveform; andinserting the contrast correction waveform into a remaining portion of the transitional pixel driving scheme; driving the electronic paper display with the transitional pixel driving scheme; and in response to determining that the rate of page transition is fixed at the second rate, driving the display with the second pixel driving scheme.