Patent ID: 9542872
Date: 2017-01-10
CPC Classifications: G09G

Claim:
1. A data driver for an electrophoretic display (EPD), comprising a plurality of driver sub-circuits, each of the driver sub-circuits driving a pixel column of the EPD in a driving period via a driver end; wherein each of the driver sub-circuits comprises: an output node; a first latch and a second latch, for respectively storing updated latch image data and current latch image data in response to original image data, the second latch further providing the current latch image data to the output node, the updated latch image data and the current latch image data each selectively corresponding individually to one of a positive reference level, a negative reference level and a ground reference level; a multiplexer, coupled to a first capacitor, a second capacitor, the output node and the driver end; and a comparator, dividing the driving period into a first period, a second period and a third period, wherein when the updated latch image data and the current latch image data selectively correspond to different levels, the comparator controls the multiplexer to selectively couple one of the first and second capacitors to the driver end in the first period to recycle charges at the pixel column into the coupled one of the first and second capacitors, and to selectively couple said one of the first and second capacitors to the driver end in the second period to pre-charge or pre-discharge the pixel column with the recycled charges in the coupled one of the first and second capacitors, wherein when the current latch image data correspond to the positive reference level, and the updated and current latch image data correspond to different levels, the comparator controls the multiplexer to couple the first capacitor to the driver end in the first period to recycle positive charges at the pixel column to the first capacitor.