Display systems and methods

Patent metadata

Field	Value
Publication number	US-2016240148-A1
Application number	US-201415027421-A
Country	US
Kind code	A1
Filing date	Oct 29, 2014
Priority date	Oct 30, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

A method of displaying colour data on an electronic paper display is displayed. The method comprises providing an electronic paper display having display pixels at a display pixel pitch and providing a colour filter for said display. Said colour filter comprises groups of coloured filter elements, each said coloured filter element having one of a plurality of different colours, wherein each group of coloured filter elements defines a pattern of said coloured filter elements. In said pattern a coloured filter element overlies an integral number, n, of said display pixels, where n is two or more. The method also comprises providing colour image data defining a plurality of colour image planes, one for each of said different colours. Data in a said colour image plane comprises image pixel data defining values for image pixels corresponding to said display pixels. The method also comprises selecting, from said data in each said colour image plane, data for image pixels corresponding to display pixels over which the filter elements of the respective colour for the colour plane lie; and using said selected data to drive said electronic paper display; wherein on said display a rate of spatial variation of said selected data for said image pixels is less than said display pixel pitch.

First claim

1 . A method of displaying colour data on an electronic paper display, the method comprising:
providing an electronic paper display having display pixels at a display pixel pitch; providing a colour filter for said display, said colour filter comprising groups of coloured filter elements, each said coloured filter element having one of a plurality of different colours, wherein each group of coloured filter elements defines a pattern of said coloured filter elements, and wherein in said pattern a coloured filter element overlies an integral number, n, of said display pixels, where n is two or more; providing colour image data defining a plurality of colour image planes, one for each of said different colours, wherein data in a said colour image plane comprises image pixel data defining values for image pixels corresponding to said display pixels; selecting, from said data in each said colour image plane, data for image pixels corresponding to display pixels over which the filter elements of the respective colour for the colour plane lie; and using said selected data to drive said electronic paper display; wherein on said display a rate of spatial variation of said selected data for said image pixels is less than said display pixel pitch.

2 . A method as claimed in claim 1 further comprising combining said selected data for a set, c, comprising c different colour planes of said plurality of different said colour planes, and driving a row of said display using said combined data; wherein a ratio of said spatial variation of said selected data for one of said colours along said row is

1

n
×
c

of a rate of
spatial variation defined by said pitch of said display pixels along said row.

3 . A method as claimed in claim 2 comprising four different said colour planes, with c=2 of said colour planes combined along said row, wherein said coloured filter element overlies n=2 said display pixels along said row, and wherein said ratio of said spatial variation of said selected data for one of said colour planes combined along said row is one half of said rate of spatial variation defined by said pitch of said display pixels along said row.

4 . A method as claimed in claim 1 wherein selecting comprises determining combined output data for a row of said display using:
Out( i,j )= Rm ( i,j,R )* I ( i,j,R )+ Gm ( i,j,G )* I ( i,j,G )+ Bm ( i,j )* I ( i,j,B )+ Wm ( i,j )* I ( i,j,W )
where i,j define row and column display pixel coordinates, I(i,j,R), I(i,j,G), I(i,j,B), I(i,j,W) are red, green, blue, and white colour image plane data, and Rm(i,j), Gm(i,j), Bm(i,j), Wm(i,j) are respectively red, green, blue and white colour masks representing coordinates of respective red, green, blue and white said coloured filter elements.

5 . A method as claimed in claim 1 further comprising receiving electronic document data, and rendering content of said electronic document data for display at a spatial resolution of said display pixels by converting said electronic document data to said colour image data such that each colour plane of said colour image data defines data at said spatial resolution of said display pixels.

6 . A method as claimed in claim 1 wherein said different colours include white.

7 . A method as claimed in claim 1 wherein said colour filter pattern comprises a pattern of four display pixels by four display pixels comprising four squares, each of four display pixels, each square defining a different said colour for a said coloured filter element.

8 . An electronic paper display having display pixels at a display pixel pitch, further comprising a colour filter for said display, said colour filter comprising groups of coloured filter elements, each said coloured filter element having one of a plurality of different colours, wherein each group of coloured filter elements defines a pattern of said coloured filter elements, and wherein in said pattern a coloured filter element overlies an integral number, n, of said display pixels, where n is two or more.

9 . An electronic paper display as claimed in claim 8 , wherein said colour filter pattern comprises a pattern of four display pixels by four display pixels comprising four squares, each of four display pixels, each square defining a different said colour for a said coloured filter element.

10 . A controller for the electronic paper display of claim 8 , the controller comprising:
an input to receive colour image data defining a plurality of colour image planes, one for each of said different colours, wherein data in a said colour image plane comprises image pixel data defining values for image pixels corresponding to said display pixels; a system to select, from said data in each said colour image plane, data for image pixels corresponding to display pixels over which the filter elements of the respective colour for the colour plane lie; and an output to combine said selected data into row/column data for driving pixels of said electronic paper display; wherein on said display, when driven, a rate of spatial variation of said selected data for said image pixels is less than said display pixel pitch.

11 . A controller as claimed in claim 10 in combination with a driver to provide waveforms for driving said electronic paper display.

12 . A controller, as recited in claim 10 , wherein said electronic paper display is an electrophoretic display.

13 . A controller as recited in claim 10 , wherein said electronic paper display comprises a flexible display having a backplane comprising an active matrix of organic field effect transistors, and wherein pixels of said display are driven by drain/source connections of said transistors with respect to a common pixel electrode of said backplane.

14 . An electric field controlled display such as an electrophoretic or electrowetting display having a colour filter, wherein colour sub-pixels of said filter are larger than native pixels of said display.

15 . A display as claimed in claim 14 wherein colour sub-pixels of said filter have a size in at least one dimension which is an integral multiple, equal to or greater than two, of a size of said native pixels of said display in said at least one dimension.

16 . A consumer electronic device, in particular an electronic document reading device, incorporating a display as recited in claim 8 .

17 . A display as recited in claim 8 wherein said electronic paper display is an electrophoretic display.

18 . A method as recited in claim 1 wherein said electronic paper display is an electrophoretic display.

19 . A display as recited in claim 8 , wherein said electronic paper display comprises a flexible display having a backplane comprising an active matrix of organic field effect transistors, and wherein pixels of said display are driven by drain/source connections of said transistors with respect to a common pixel electrode of said backplane.

20 . A method as recited in claim 1 , wherein said electronic paper display comprises a flexible display having a backplane comprising an active matrix of organic field effect transistors, and wherein pixels of said display are driven by drain/source connections of said transistors with respect to a common pixel electrode of said backplane.

Assignees

• Flexenable Ltd

Inventors

• Reeves William

Classifications

• G09G2320/0613

  The adjustment depending on the type of the information to be displayed · CPC title

• G09G2320/0242

  Compensation of deficiencies in the appearance of colours · 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

• G09G3/348

  based on the deformation of a fluid drop, e.g. electrowetting · CPC title

• G09G2380/14

  Electronic books and readers · CPC title