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US 11,686,989 B2Granted
Four particle electrophoretic medium providing fast, high-contrast optical state switching
AssigneeE Ink Corporation
InventorsStephen J. Telfer, Yuval Ben-Dov, Teck Ping Sim, Sherry Hsin-Yi Tsai
Life of this patent
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Abstract
Improved electrophoretic media including a first particle of a first polarity and three particles of the opposite polarity, wherein the first particle and optionally one of the particles of the opposite polarity undergo a diminution of electrophoretic mobility with increased electric field. Such electrophoretic media enable full-color displays with very fast updates between white and black pixels.
Claims24
An electrophoretic medium comprising a non-polar fluid and including:
- a first type of particle having a first optical property and a first charge polarity;
- a second type of particle having a second optical property, and having a second charge polarity opposite to the first charge polarity with a first charge magnitude, the second type of particle having a surface coating of polymer that is covalently bound to the particle;
- a third type of particle having a third optical property, and having the second charge polarity with a second charge magnitude smaller than the first charge magnitude;
- and
- a fourth type of particle having a fourth optical property, and having the second charge polarity with a third charge magnitude larger than the first charge magnitude,
- wherein the third type of particle and the fourth type of particle both include a layer of polymer complexed to the particle.
3 more elements
An electrophoretic medium comprising a non-polar fluid and including:
- a first type of particle having a first optical property and a first charge polarity;
- a second type of particle having a second optical property, and having a second charge polarity opposite to the first charge polarity with a first charge magnitude, the second particle having no surface coating of polymer;
- a third type of particle having a third optical property, and having the second charge polarity with a second charge magnitude smaller than the first charge magnitude;
- and
- a fourth type of particle having a fourth optical property, and having the second charge polarity with a third charge magnitude larger than the first charge magnitude,
- wherein the third type of particle and the fourth type of particle both include a layer of polymer complexed to the particle.
3 more elements
An electrophoretic medium comprising a non-polar fluid and including:
- a first type of particle having a first optical property and a first charge polarity;
- a second type of particle having a second optical property, and having a second charge polarity opposite to the first charge polarity with a first charge magnitude, the second type of particle having greater than 200 mg of a charge control agent (CCA) adsorbed onto the second type of particle for each gram of the second type of particle in the electrophoretic medium;
- a third type of particle having a third optical property, and having the second charge polarity with a second charge magnitude smaller than the first charge magnitude;
- and
- a fourth type of particle having a fourth optical property, and having the second charge polarity with a third charge magnitude larger than the first charge magnitude,
- wherein the third type of particle and the fourth type of particle each have less than 50 mg of a charge control agent (CCA) adsorbed onto the third and fourth types of particles for each respective gram of third and fourth types of particles in the electrophoretic medium.
3 more elements
A four-particle electrophoretic medium for use in a color electrophoretic display, comprising:
- a non-polar fluid;
- and
- a four-particle system comprising four types of electrophoretic particles dispersed in the non-polar fluid, said four types of particles comprising:
- a first type of particle having a first optical property and a first charge polarity;
- a second type of particle having a second optical property, and having a second charge polarity with a first charge magnitude, said second charge polarity being opposite to the first charge polarity;
- a third type of particle having a third optical property, and having the second charge polarity with a second charge magnitude smaller than the first charge magnitude;
- and
- a fourth type of particle having a fourth optical property, and having the second charge polarity with a third charge magnitude larger than the first charge magnitude;
- wherein the first type of particle and only one of the second, third, and fourth types of particles are configured to undergo a diminution in electrophoretic mobility with an increased electric field, and
- wherein the first type of particle is white, and the second, third, and fourth types of particles are selected from cyan, magenta, and yellow.
7 more elements
Dependencies are inferred from the claim text.