Image display medium and image display device

• US 8,174,491 B2
• Filed: 02/21/2008
• Issued: 05/08/2012
• Est. Priority Date: 06/05/2007
• Status: Active Grant

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Machida, Yoshinori, Suwabe, Yasufumi, Tatsuura, Satoshi, Abe, Masaaki, Shigehiro, Kiyoshi
• Primary Examiner(s): DINH, DUC Q
• Application Number:
  US12/034,859
• Publication Number:
  US 20080303779A1
• Time in Patent Office: 1,538 Days
• Field of Search: 345/107
• US Class Current: 345/107
• CPC Class Codes: G09G 2320/0252 Improving the response speed
• CPC Class Codes: G09G 3/3446 with more than two electrodes controlling the modulating element

Abstract

An image display medium including a pair of substrates, a transparent dispersion medium, one or more kind of colored particles and larger sized colored particles. The pair of substrates is disposed with a separation therebetween and at least one of the pair of substrates is transparent. The dispersion medium is transparent and enclosed between the pair of substrates. Each kind of the colored particles is colored a predetermined color, is dispersed in the dispersion medium, has predetermined charge characteristics or predetermined magnetic properties, and is able to migrate between the pair of substrates. The larger sized colored particles have a different color and a larger particle size than the colored particles, are disposed so that the colored particles are able to pass through the separation, have charge characteristics or magnetic properties which are different from those of the colored particles, and are able to move.

Claims

1. An image display medium comprising:

a pair of substrates, disposed with a separation therebetween, at least one of the pair of substrates being transparent;

a transparent dispersion medium that is enclosed between the pair of substrates;

one or more kind of colored particles, each kind of the colored particles being colored a predetermined color and being dispersed in the dispersion medium, each kind of the colored particles having predetermined charge characteristics or predetermined magnetic properties and being able to migrate between the pair of substrates; and

larger sized colored particles that have a different color and a larger particle size than those of the colored particles, the larger sized colored particles being disposed so that the colored particles are able to pass through the separation, the larger sized colored particles having charge characteristics or magnetic properties which are different from the colored particles, and the larger sized colored particles being able to move, wherein

the image display medium includes an amount of larger sized colored particles such that a substantially whole visible area of a view side of the pair of substrates can be covered by at least one layer of the larger sized colored particles.

2. An image display device comprising:

a pair of substrates, disposed with a separation therebetween, at least one of the pair of substrates being transparent;

a transparent dispersion medium that is enclosed between the pair of substrates;

one or more kind of colored particles, each kind of the colored particles being colored a predetermined color and being dispersed in the dispersion medium, each kind of the colored particles having predetermined charge characteristics or predetermined magnetic properties and being able to migrate between the pair of substrates;

larger sized colored particles that have a different color and a larger particle size than those of the colored particles, the larger sized colored particles being disposed so that the colored particles are able to pass through the separation, the larger sized colored particles having charge characteristics or magnetic properties which are different from the colored particles, and the larger sized colored particles being able to move;

a migration force applying unit that migrates the colored particles; and

a movement force applying unit that moves the larger sized colored particles, wherein

the image display medium includes an amount of larger sized colored particles such that a substantially whole visible area of a view side of the pair of substrates can be covered by at least one layer of the larger sized colored particles.

3. The image display device according to claim 2, wherein, when the larger sized colored particles have the predetermined charge characteristic, the movement force applying unit is an electric field generator that forms an electric field between the pair of substrates.

4. The image display device according to claim 2, wherein, when the larger sized colored particles have the predetermined magnetic properties, the movement force applying unit is a magnetic field generator that forms a magnetic field between the pair of substrates.

5. The image display device according to claim 2, wherein, when the colored particles have the predetermined charge characteristic, the migration force applying unit is an electric field generator that forms an electric field between the pair of substrates.

6. The image display device according to claim 2, wherein, when the colored particles have the predetermined magnetic properties, the migration force applying unit is a magnetic field generator that forms a magnetic field between the pair of substrates.

7. The image display device according to claim 2, wherein, when the colored particles and the larger sized colored particles have different respective charge characteristics from each other, an electric field generator that forms an electric field between the pair of substrates serves both as the migration force applying unit and as the movement force applying unit.

8. The image display device according to claim 7, wherein a stronger electric field is required to move the larger sized colored particles compared to the electric field strength that is required in order to migrate the colored particles.

9. The image display device according to claim 2, wherein, when the colored particles and the larger sized colored particles have different respective magnetic properties from each other, a magnetic field generator that forms a magnetic field between the pair of substrates serves both as the migration force applying unit and as the movement force applying unit.

10. The image display device according to claim 9, wherein a stronger magnetic field is required to move larger sized colored particles than the magnetic field strength required to migrate the colored particles.

11. The image display device according to claim 2, wherein the movement force applying unit is a vibration applying unit which imparts vibration mechanically.

14. The image display device according to claim 2, wherein the larger sized colored particles are substantially white in color.

15. The image display device according to claim 2, wherein the larger sized colored particles comprise a binder resin and a material with a larger specific gravity than that of the binder resin.

16. The image display device according to claim 2, wherein the colored particles are migrated by the migration force applying unit at the same time as the larger sized colored particles are moved by the movement force applying unit.

17. The image display device according to claim 2, wherein the colored particles are migrated by the migration force applying unit after the larger sized colored particles are moved by the movement force applying unit.

12. An image display device comprising:

a pair of substrates, disposed with a separation therebetween, at least one of the pair of substrates being transparent;

a transparent dispersion medium that is enclosed between the pair of substrates;

one or more kind of colored particles, each kind of the colored particles being colored a predetermined color and being dispersed in the dispersion medium, each kind of the colored particles having predetermined charge characteristics or predetermined magnetic properties and being able to migrate between the pair of substrates;

larger sized colored particles that have a different color and a larger particle size than those of the colored particles, the larger sized colored particles being disposed so that the colored particles are able to pass through the separation, the larger sized colored particles having charge characteristics or magnetic properties which are different from the colored particles, and the larger sized colored particles being able to move;

a migration force applying unit that migrates the colored particles; and

a movement force applying unit that moves the larger sized colored particles, wherein

the larger sized colored particles have at least a portion that is a distance from the center of gravity thereof and that is charged with a positive or a negative polarity, and the larger sized colored particles are particles of a rotational body shape that rotate according to an electric field that is formed between the substrates, and the movement force applying unit is an electric field generator that forms an electric field between the pair of substrates.

13. An image display device comprising:

a pair of substrates, disposed with a separation therebetween, at least one of the pair of substrates being transparent;

a transparent dispersion medium that is enclosed between the pair of substrates;

one or more kind of colored particles, each kind of the colored particles being colored a predetermined color and being dispersed in the dispersion medium, each kind of the colored particles having predetermined charge characteristics or predetermined magnetic properties and being able to migrate between the pair of substrates;

larger sized colored particles that have a different color and a larger particle size than those of the colored particles, the larger sized colored particles being disposed so that the colored particles are able to pass through the separation, the larger sized colored particles having charge characteristics or magnetic properties which are different from the colored particles, and the larger sized colored particles being able to move;

a migration force applying unit that migrates the colored particles; and

a movement force applying unit that moves the larger sized colored particles, wherein

the larger sized colored particles have at least a portion that is a distance from the center of gravity thereof and that is a magnetic N pole or a magnetic S pole, and the larger sized colored particles are particles of a rotational body shape that rotate according to a magnetic field that is formed between the substrates, and the movement force applying unit is a magnetic field generator that forms a magnetic field between the pair of substrates.

18. An image display medium comprising:

a pair of substrates, disposed with a separation therebetween, at least one of the pair of substrates being transparent;

a transparent dispersion medium that is enclosed between the pair of substrates;

one or more kind of colored particles, each kind of the colored particles being colored a predetermined color and being dispersed in the dispersion medium, each kind of the colored particles having predetermined charge characteristics or predetermined magnetic properties and being able to migrate between the pair of substrates; and

larger sized colored particles that have a different color and a larger particle size than those of the colored particles, the larger sized colored particles being disposed so that the colored particles are able to pass through the separation, the larger sized colored particles having charge characteristics or magnetic properties which are different from the colored particles, and the larger sized colored particles being able to move, wherein

the image display medium includes an amount of larger sized colored particles such that a substantially whole visible area of a view side of the pair of substrates can be covered by at least one layer of the larger sized colored particles, and

the larger sized color particles are in substantially a single size.

19. An image display device comprising:

a pair of substrates, disposed with a separation therebetween, at least one of the pair of substrates being transparent;

a transparent dispersion medium that is enclosed between the pair of substrates;

one or more kind of colored particles, each kind of the colored particles being colored a predetermined color and being dispersed in the dispersion medium, each kind of the colored particles having predetermined charge characteristics or predetermined magnetic properties and being able to migrate between the pair of substrates;

larger sized colored particles that have a different color and a larger particle size than those of the colored particles, the larger sized colored particles being disposed so that the colored particles are able to pass through the separation, the larger sized colored particles having charge characteristics or magnetic properties which are different from the colored particles, and the larger sized colored particles being able to move;

a migration force applying unit that migrates the colored particles; and

a movement force applying unit that moves the larger sized colored particles, wherein

the image display medium includes an amount of larger sized colored particles such that a substantially whole visible area of a view side of the pair of substrates can be covered by at least one layer of the larger sized colored particles, and

the larger sized color particles are in substantially a single size.