Methods for driving electro-optic displays

Patent metadata

Field	Value
Publication number	US-2016133196-A1
Application number	US-201414447707-A
Country	US
Kind code	A1
Filing date	Jul 31, 2014
Priority date	Jul 31, 2013
Publication date	May 12, 2016
Grant date	—

Abstract

There are provided display controllers and driving methods related to those described in US Published Patent Application No. 2013/0194250. These include (a) a display controller having an update buffer, means for removing from the update buffer pixels not requiring updating, and means to ensure that pixels having certain special states are not removed from the update buffer; (b) a method of driving a bistable display wherein, in a pixel undergoing a white-to-white transition and lying adjacent another pixel undergoing a visible transition, there is applied to the pixel one or more balanced pulse pairs and at least one top-off pulse; (c) a method of driving a bistable display by overlaying a non-rectangular item over a pre-existing image content and then removing the item, where only pixels in the region of the item perform transitions (including self-transitions); and (d) a method of driving a bistable display in which a proportion of background pixels not undergoing an optical change are subjected to a refresh pulse to correct optical state drift.

First claim

1 . A display controller capable of controlling the operation of a bistable electro-optic display and having an update buffer, means for removing from the update buffer pixels which do not require updating during a given transition, means for receiving a list of states that should not be removed from the update buffer, and means to ensure that pixels having listed states are not removed from the update buffer.

2 . A display controller capable of controlling the operation of a bistable electro-optic display and having an update buffer, and means for removing from the update buffer pixels which do not require updating during a given transition, the controller having at least one special transition having two states associated therewith, means to determine when a pixel is undergoing a special transition immediately after a previous special transition, and means to insert into the update buffer the second state associated with the at least one special transition when a pixel is undergoing a special transition immediately after a previous special transition.

3 . A display controller according to claim 1 wherein the specified drive method is applied only to pixels within one or more defined regions of the display and a different drive scheme is applied to pixels outside the defined region or regions.

4 . A bistable electro-optic display comprising a drive controller according to claim 1 .

5 . An electro-optic display according to claim 4 comprising a rotating bichromal member, electrochromic or electro-wetting material.

6 . An electro-optic display according to claim 4 comprising an electrophoretic material comprising a plurality of electrically charged particles disposed in a fluid and capable of moving through the fluid under the influence of an electric field.

7 . An electro-optic display according to claim 6 wherein the electrically charged particles and the fluid are confined within a plurality of capsules or microcells.

8 . An electro-optic display according to claim 6 wherein the electrically charged particles and the fluid are present as a plurality of discrete droplets surrounded by a continuous phase comprising a polymeric material.

9 . An electro-optic display according to claim 6 wherein the fluid is gaseous.

10 . An electronic book reader, portable computer, tablet computer, cellular telephone, smart card, sign, watch, shelf label, variable transmission window or flash drive comprising a display according to claim 4 .

11 . A method of driving a bistable electro-optic display having a plurality of pixels wherein, in a pixel undergoing a white-to-white transition and lying adjacent at least one other pixel undergoing a readily visible transition, there is applied to the pixel one or more balanced pulse pairs and at least one top-off pulse, wherein each balanced pulse pair comprises a pair of drive pulses of opposing polarities such that the net impulse of the balanced pulse pair is substantially zero.

12 . A method according to claim 11 wherein the combination of one or more balanced pulse pairs and at least one top-off pulse is applied only when the display is above a predetermined temperature.

13 . A method according to claim 11 wherein the top-off pulse comprises a single white-going drive pulse.

14 . A method according to claim 11 where only a single top-off pulse is applied to the pixel.

15 . A display controller or electro-optic display arranged to carry out the method of claim 11 .

16 . A method of driving a bistable electro-optic display comprising overlaying a non-rectangular item over pre-existing text or image content followed by removal of the item, wherein only pixels in the region of the item perform transitions (including self-transitions).

17 . A method according to claim 16 wherein the item includes at least one transparent region, and wherein only pixels in the non-transparent regions of the item perform transitions (including self-transitions).

18 . A display controller or electro-optic display arranged to carry out the method of claim 16 or 17 .

19 . A method of driving a bistable electro-optic display having a plurality of pixels each capable of displaying two extreme optical states, the method comprising:
writing a first image on the display; writing a second image on the display using a drive scheme in which a plurality of background pixels which are in the same extreme optical state in both the first and second images are not driven; leaving the display undriven for a period of time, thereby permitting the background pixels to assume an optical state different from their extreme optical state; after said period of time, applying to a first non-zero proportion of the background pixels a refresh pulse which substantially restores the pixels to which it is applied to their extreme optical state, said refresh pulse not being applied to the background pixels other than said first non-zero proportion thereof; and thereafter, applying to a second non-zero minor proportion of the background pixels different from the first non-zero proportion a refresh pulse which substantially restores the pixels to which it is applied to their extreme optical state, said refresh pulse not being applied to the background pixels other than said second non-zero proportion thereof.

20 . A method according to claim 19 wherein the display is provided with a timer which establishes a minimum time interval between successive applications of the refresh pulses to differing non-zero proportions of the background pixels.

21 . A method according to claim 19 wherein the refresh pulses are applied to pixels in the white extreme optical state.

22 . A display controller or electro-optic display arranged to carry out the method of claim 19 .

Assignees

• E Ink Corp

Inventors

• Emelie Pierre-Yves
• Crounse Kenneth R
• Amundson Karl Raymond
• Ben-Dov Yuval
• Sim Teck Ping
• O'Malley Timothy J

Classifications

• G09G3/3433 Primary

  using light modulating elements actuated by an electric field and being other than liquid crystal devices and electrochromic devices (using liquid crystal devices G09G3/36; using electrochromic devices G09G3/38) · CPC title

• G09G2300/06

  Passive matrix structure, i.e. with direct application of both column and row voltages to the light emitting or modulating elements, other than LCD or OLED · CPC title

• G09G2310/04

  Partial updating of the display screen · CPC title

• G09G2310/08

  Details of timing specific for flat panels, other than clock recovery · CPC title

• G09G3/344 Primary

  based on particles moving in a fluid or in a gas, e.g. electrophoretic devices (electrophoretic devices per se G02F1/167) · CPC title