IP Library Granted Patent US 7,880,955
Granted Patent B2
US 7,880,955 · App. 12/483,448 · Granted Feb 1, 2011

Electrophoretic dispersion solution, image display medium using the same, and image display device using the same

Assignee: Ricoh Company, Ltd.
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Quick Facts
Patent No.
US 7,880,955
App. No.
12/483,448
Granted
Feb 1, 2011
Kind
B2
Abstract

An electrophoretic dispersion solution includes a nonpolar solvent and plural kinds of electrophoretic particles. At least one kind of the electrophoretic particles has, on surfaces, a copolymer including a first monomer that has a charged group and a second monomer expressed by a first formula represented as R denotes a hydrogen atom or a methyl group, R′ denotes a hydrogen atom or an alkyl group with a carbon number of 1 through 4, n is a natural number, and x denotes an integer of 1 through 3. At least another kind of the electrophoretic particles include, on surfaces, a polymer including a third monomer expressed by a second formula represented as a component of the polymer. R denotes a hydrogen atom or a methyl group and R″″ denotes an alkyl group with a carbon number of 4 or larger.

Claims (22)

1. An electrophoretic dispersion solution comprising:

a nonpolar solvent; and

plural kinds of electrophoretic particles,

wherein at least one kind of the electrophoretic particles has, on surfaces, a copolymer including a first monomer that has a charged group and a second monomer expressed by a first formula represented as

where R denotes a hydrogen atom or a methyl group, R′ denotes a hydrogen atom or an alkyl group with a carbon number of 1 through 4, n is a natural number, and x denotes an integer of 1 through 3; and

at least another kind of the electrophoretic particles has, on surfaces, a polymer including a third monomer expressed by a second formula represented as

as a component of the polymer, where R denotes a hydrogen atom or a methyl group and R″″ denotes an alkyl group with a carbon number of 4 or larger.

2. The electrophoretic dispersion solution as claimed in claim 1 , wherein the first monomer includes a monomer expressed by a third formula represented as

where R, R 1 , and R 2 independently denote a hydrogen atom or a methyl group and x denotes an integer of 1 through 3.

3. The electrophoretic dispersion solution as claimed in claim 1 , wherein the first monomer includes a monomer expressed by a fourth formula represented as

where R denotes a hydrogen atom or a methyl group.

4. The electrophoretic dispersion solution as claimed in claim 1 , further comprising a dispersion agent.

5. An image display medium comprising:

a pair of electrodes, one of said electrodes being capable of transmitting light; and

the electrophoretic dispersion solution as claimed in claim 1 filling in between the electrodes, said electrophoretic dispersion solution being divided into plural micro spaces defined by one or more partitions.

6. An image display device comprising the image display medium as claimed in claim 5 and a control part configured to control a display of the image display medium.

7. An image display device comprising:

an image display medium including a pair of electrodes, one of said electrodes being capable of transmitting light; and an electrophoretic dispersion solution filling in between the electrodes, said electrophoretic dispersion solution including a nonpolar solvent and plural kinds of electrophoretic particles, in which at least one kind of the electrophoretic particles has, on surfaces, a copolymer including a first monomer that has a charged group and a second monomer expressed by a first formula represented as

where R denotes a hydrogen atom or a methyl group, R′ denotes a hydrogen atom or an alkyl group with a carbon number of 1 through 4, n is a natural number, and x denotes an integer of 1 through 3; and

at least another kind of the electrophoretic particles has, on surfaces, a polymer including a third monomer expressed by a second formula represented as

as a component of the polymer, where R denotes a hydrogen atom or a methyl group and R″″ denotes an alkyl group with a carbon number of 4 or larger, said electrophoretic dispersion solution being divided into plural micro spaces defined by one or more partitions; and

a control part configured to control a display of the image display medium.

Assignments (3)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 6, 2020
From: TIANMA MICRO-ELECTRONICS CO., LTD.
To: TRANSCEND OPTRONICS (YANGZHOU) CO., LTD.
Reel/Frame 055206/0250 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 28, 2016
From: RICOH COMPANY, LTD.
To: TIANMA MICRO-ELECTRONICS CO., LTD.
Reel/Frame 039871/0636 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 15, 2009
From: NAIJO, YOSHIHISA; YANAGISAWA, MASAHIRO
To: RICOH COMPANY, LTD.
Reel/Frame 022827/0032 →
Priority Claims (1)
JP 2008-174865 · Jul 3, 2008 · national
Continuity (1)
Related Publication 20100002287A1 · Jan 7, 2010