Methods for driving electro-optic displays

• US 9,721,495 B2
• Filed: 02/26/2014
• Issued: 08/01/2017
• Est. Priority Date: 02/27/2013
• Status: Active Grant

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Inventors: Harrington, Demetrious Mark, Crounse, Kenneth R., Amundson, Karl Raymond, Sim, Teck Ping, Aprea, Matthew J.
• Primary Examiner(s): Awad, Amr
• Assistant Examiner(s): Midkiff, Aaron
• Application Number:
  US14/190,135
• Publication Number:
  US 20140240373A1
• Time in Patent Office: 1,252 Days
• Field of Search: 345108, 345690, 359296, 710 57, 710 52, 711136
• CPC Class Codes: G09G 2230/00 Details of flat display driving waveforms
• CPC Class Codes: G09G 2340/16 Determination of a pixel data signal depending on the signal applied in the previous frame
• CPC Class Codes: G09G 3/2007 Display of intermediate tones
• CPC Class Codes: G09G 3/344 based on particles moving in a fluid or in a gas, e.g. electrophoretic devices electrophoretic devices per se G02F1/167

Abstract

An electro-optic display having a plurality of pixels is driven from a first image to a second image using a first drive scheme, and then from the second image to a third image using a second drive scheme different from the first drive scheme and having at least one impulse differential gray level having an impulse potential different from the corresponding gray level in the first drive scheme. Each pixel which is in an impulse differential gray level in the second image is driven from the second image to the third image using a modified version of the second drive scheme which reduces its impulse differential The subsequent transition from the third image to a fourth image is also conducted using the modified second drive scheme but after a limited number of transitions using the modified second drive scheme, all subsequent transitions are conducted using the unmodified second drive scheme.

Claims

1. An electro-optic display comprising a bistable electro-optic medium, at least two electrodes disposed adjacent the bistable electro-optic medium and arranged to apply an electric field to the medium, a display controller for controlling the potentials on the at least two electrodes, and a host controller arranged to supply video information to the display controller, the display controller comprising a frame buffer having a rotating set of image buffer regions which allow the host controller to write images to the frame buffer, the display controller being arranged to retrieve and update the display with the latest whole video frame image written by the host controller, the display controller being arranged to store:

an Image Buffer Read Pointer;

an Image Buffer Write Pointer;

an Image Buffer Empty Flag;

a Programmable Image Buffer Nearly Empty Flag; and

an Image Buffer Latest Image Pointer, which marks the location of the last complete video frame image written to the memory by the host controller and the display controller configured to retrieve and update the display with this last complete video frame image.

2. A display according to claim 1 wherein the pixels of the display are partitioned into interlaced regions each of which is updated at a time offset from the other regions.