Multiple voltage level driving for electrophoretic displays

Patent metadata

Field	Value
Publication number	US-9251736-B2
Application number	US-201313893265-A
Country	US
Kind code	B2
Filing date	May 13, 2013
Priority date	Jan 30, 2009
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

This application is directed to driving methods for electrophoretic displays. The driving methods comprise applying different voltages selected from multiple voltage levels, to pixel electrodes and optionally also to the common electrodes. In one embodiment, the different voltages are selected from a group consisting of 0V, at least two levels of positive voltage and at least two levels of negative voltage. The driving method is also suitable for a color display device.

First claim

What is claimed is:

1. A driving method for driving a color display device, which display device comprises an electrophoretic fluid sandwiched between a common electrode and a layer of pixel electrodes and the electrophoretic fluid comprises a first type of pigment particles, a second type of pigment particles and a third type of pigment particles, all of which are dispersed in a solvent or solvent mixture, wherein
(a) the first type of pigment particles and the second type of pigment particles carry opposite charge polarities;
(b) the third type of pigment particles has the same charge polarity as the second type of pigment particles but at a lower intensity; and
(c) the second type of pigment particles has a threshold voltage,

the method comprising:
applying to a pixel electrode a voltage of a high positive voltage;
applying to the pixel electrode a voltage of a high negative voltage; and
applying to the pixel electrode a voltage of a low positive voltage or a low negative voltage, which is equal to or lower than the threshold voltage, wherein when the low positive voltage or low negative voltage having the same polarity as the second type of pigment particles is applied to the pixel electrode, a voltage potential difference between the common electrode and the pixel electrode drives an area corresponding to the pixel electrode to a color state of the third type of pigment particles, at a viewing side, from a color state of the first type of pigment particles.

2. The driving method of claim 1 , wherein the first type of pigment particles and the second type of pigment particles are black and white respectively, or vice versa.

3. The driving method of claim 2 , wherein the third type of pigment particles is non-white and non-black.

4. The driving method of claim 3 , wherein the third type of pigment particles is red, green, blue, yellow, magenta or cyan.

5. The driving method of claim 1 , wherein no voltage is applied to the common electrode.

6. The driving method of claim 1 , wherein the magnitude of the low positive or negative voltage is about 5% to about 50% of the magnitude of the high positive or negative voltage.

7. The driving method of claim 1 , wherein the first type of pigment particles is negatively charged and the second and third type of pigment particles are positively charged,
when the high positive voltage is applied to a pixel electrode, the voltage potential difference between the common electrode and the pixel electrode drives an area corresponding to the pixel electrode to the color state of the second type of pigment particles, at the viewing side; or
when the high negative voltage is applied to a pixel electrode, the voltage potential difference between the common electrode and the pixel electrode drives an area corresponding to the pixel electrode to the color state of the first type of pigment particles, at the viewing side; or
when the low positive voltage is applied to a pixel electrode, the voltage potential difference between the common electrode and the pixel electrode drives an area corresponding to the pixel electrode to the color state of the third type of pigment particles, at the viewing side, from the color state of the first type of pigment particles.

8. The driving method of claim 1 , wherein the first type of pigment particles is positively charged and the second and third type of pigment particles are negatively charged,
when the high positive voltage is applied to a pixel electrode, the voltage potential difference between the common electrode and the pixel electrode drives an area corresponding to the pixel electrode to the color state of the first type of pigment particles, at the viewing side; or
when the high negative voltage is applied to a pixel electrode, the voltage potential difference between the common electrode and the pixel electrode drives an area corresponding to the pixel electrode to the color state of the second type of pigment particles, at the viewing side; or
when the low negative voltage is applied to a pixel electrode, the voltage potential difference between the common electrode and the pixel electrode drives an area corresponding to the pixel electrode to the color state of the third type of pigment particles, at the viewing side, from the color state of the first type of pigment particles.

Assignees

• Sipix Imaging Inc
• E Ink California Llc

Inventors

• Lin Craig
• Pham Tin
• Chan Bryan
• Peri Manasa
• Wang Ming
• Li Yu
• Du Hui
• Zhang Xiaojia

Classifications

• G09G3/3291 Primary

  in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements · 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

• G02F1/167

  by electrophoresis · CPC title

• G09G3/2011

  by amplitude modulation · CPC title

• G09G3/2003

  Display of colours (specific for liquid crystal displays G09G3/3607) · CPC title