Method of making uniformly magnetized elements for a gyricon display

• US 6,097,531 A
• Filed: 11/25/1998
• Issued: 08/01/2000
• Est. Priority Date: 11/25/1998
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Sheridon, Nicholas K.
• Primary Examiner(s): Ben, Loha
• Application Number:
  US09/199,646
• Time in Patent Office: 615 Days
• Field of Search: 359/296, 359/265, 359/273, 264/8, 264/15, 264/5, 264/10, 264/437, 264/429, 264/4.1, 434/409, 425/8
• US Class Current: 359/296
• CPC Class Codes: G02B 26/026 based on the rotation of particles under the influence of an external field, e.g. gyricons, twisting ball displays based on orientable dipolar particles G02F1/172; based on electrophoresis G02F1/167
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field
• CPC Class Codes: G09F 9/375 the position of the elements being controlled by the application of a magnetic field

Abstract

A method of forming magnetized rotating elements for a rotating element display where all the elements are magnetized in the same orientation is provided. First, at least two planar streams of hardenable liquids flowing in substantially the same direction are provided. Each stream has an associated optical modulation characteristic and at least one stream has an associated optical modulation characteristic different from at least one other stream. At least one stream includes a magnetic pigment. The streams are then merged to form a reservoir containing side-by-side amounts of each liquid from each stream. A free jet is then formed containing side-by-side amounts of each liquid from the reservoir. Then a portion of the free jet is passed through a magnetic field which is oriented transverse to the direction of the free jet to magnetize the magnetic pigment. The rotating elements formed can be either spherical in shape or cylindrical in shape. In either case, each element will be comprised of side-by-side segments. To form spherical elements the free jet can be broken into spherical portions either before or after the magnetic pigment has been magnetized. Ultimately, magnetized spherical portions of the free jet are hardened into rotating spherical elements and collected. To form cylindrical elements, the free jet is magnetized and hardened into a filament The filament is then collected and broken into cylindrical elements.

Claims

1. A method of forming rotating elements for a rotating element display comprising:

a) providing at least two planar streams of hardenable liquids flowing in substantially the same direction, each stream being associated with an optical modulation characteristic wherein at least one stream has an associated optical modulation characteristic different from at least one other stream and at least one stream includes a magnetic pigment,

b) merging the streams to form a reservoir containing side-by-side amounts of each liquid,

c) forming a free jet containing side-by-side amounts of each liquid from the reservoir, and

d) passing at least a portion of the free jet through a magnetic field aligned transverse to the free jet to magnetize the magnetic pigment.

2. The method of claim 1 further comprising the step of:

a) hardening the free jet to form a filament having at least two segments, each segment being due to a single planar stream, the at least two segments being joined at a planar interface, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment and at least one segment is magnetized.

3. The method of claim 2 further comprising the step of:

a) separating the filament into a plurality of substantially cylindrical elements comprised of at least two segments each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, at least one segment is magnetized in a given orientation, each substantially cylindrical element has an anisotropy for providing an electrical dipole moment, the electrical dipole moment rendering the substantially cylindrical element electrically responsive such that when the substantially cylindrical element is rotatably disposed in an electric field while the electrical dipole moment of the substantially cylindrical element is provided, the substantially cylindrical element tends to rotate to an orientation in which the electrical dipole moment aligns with the field, and wherein the magnetized segments of the plurality of substantially cylindrical hardened elements are magnetized in substantially the same orientation.

4. The method of claim 3 wherein three planar streams were provided and the plurality of substantially cylindrical elements comprise three segments.

5. The method of claim 4 wherein two of the planar streams contained magnetic pigment and the plurality of substantially cylindrical elements comprise three segments, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, and two segments are magnetized in a given substantially similar orientation.

6. The method of claim 3 wherein four planar streams were provided and the plurality of substantially cylindrical elements comprise four segments.

7. The method of claim 6 wherein two of the planar streams contained magnetic pigment and the plurality of substantially cylindrical elements comprise three segments, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, and two segments are magnetized in a given substantially similar orientation.

8. The method of claim 1 wherein the step of forming a free jet comprises forming a plurality of free jets and the step of passing the free jet through a magnetic field comprises passing the plurality of free jets through the magnetic field wherein the free jets are substantially oriented in the same direction with respect to the magnetic field.

9. The method of claim 8 further comprising the step of:

hardening the plurality of free jets to form a plurality of filaments, each filament having at least two segments, each segment being due to a single planar stream, the at least two segments being joined at a planar interface, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, at least one segment is magnetized, and wherein the magnetized segments of the plurality of filaments are magnetized in substantially the same orientation.

10. The method of claim 9 further comprising the step of:

a) separating the plurality of filaments into a plurality of substantially cylindrical elements, each element comprised of at least two segments each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, at least one segment is magnetized in a given orientation, each substantially cylindrical element has an anisotropy for providing an electrical dipole moment, the electrical dipole moment rendering the substantially cylindrical element electrically responsive such that when the substantially cylindrical element is rotatably disposed in an electric field while the electrical dipole moment of the substantially cylindrical element is provided, the substantially cylindrical element tends to rotate to an orientation in which the electrical dipole moment aligns with the field, and wherein the magnetized segments of the plurality of substantially cylindrical elements are magnetized in substantially the same orientation.

11. The method of claim 1 further comprising the step of:

a) forming a plurality of substantially spherical portions of the free jet, each portion having at least two segments, each segment being due to a single planar stream, the at least two segments being joined at a planar interface, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment and at least one segment is magnetized, and wherein the magnetized segments of the plurality of substantially spherical portions are magnetized in substantially the same orientation, and

b) hardening the plurality of substantially spherical portions to form substantially spherical elements, each substantially spherical element being comprised of at least two segments each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, at least one segment is magnetized in a given orientation, each substantially spherical element has an anisotropy for providing an electrical dipole moment, the electrical dipole moment rendering the substantially spherical element electrically responsive such that when the substantially spherical element is rotatably disposed in an electric field while the electrical dipole moment of the substantially spherical element is provided, the substantially spherical element tends to rotate to an orientation in which the electrical dipole moment aligns with the field, and wherein the magnetized segments of the plurality of substantially spherical elements are magnetized in substantially the same orientation.

12. The method of claim 1 further comprising the steps of:

a) forming a plurality of substantially spherical portions of the free jet, each portion having at least two segments, each segment being due to a single planar stream, the at least two segments being joined at a planar interface, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment and at least one segment contains magnetic pigment such that the plurality of substantially spherical portions pass through the magnetic field in substantially the same orientation with respect to the magnetic field, and

b) hardening the plurality of magnetized substantially spherical portions to form substantially spherical elements, each substantially spherical element being comprised of at least two segments each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, at least one segment is magnetized in a given orientation, each hardened substantially spherical element has an anisotropy for providing an electrical dipole moment, the electrical dipole moment rendering the substantially spherical element electrically responsive such that when the substantially spherical element is rotatably disposed in an electric field while the electrical dipole moment of the substantially spherical element is provided, the substantially spherical element tends to rotate to an orientation in which the electrical dipole moment aligns with the field, and wherein the magnetized segments of the plurality of substantially spherical hardened elements are magnetized in substantially the same orientation.

13. The method of claim 12 wherein three planar streams were provided and the plurality of substantially spherical elements comprise three segments.

14. The method of claim 13 wherein two of the planar streams contained magnetic pigment and the plurality of substantially spherical elements comprise three segments, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, and two segments are magnetized in a given substantially similar orientation.

15. The method of claim 12 wherein four planar streams were provided and the plurality of substantially spherical elements comprise four segments.

16. The method of claim 15 wherein two of the planar streams contained magnetic pigment and the plurality of substantially spherical elements comprise three segments, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, and two segments are magnetized in a given substantially similar orientation.

17. The method of claim 1 further comprising the steps of:

a) forming a plurality of substantially spherical portions of the free jet, each portion having at least two segments, each segment being due to a single planar stream, the at least two segments being joined at a planar interface, each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment and at least one segment contains magnetic pigment,

b) hardening the plurality of substantially spherical portions just formed, each hardened substantially spherical portion being comprised of at least two segments each segment being associated with an optical modulation characteristic wherein at least one segment has an associated optical modulation characteristic different from at least one other segment, at least one segment is magnetized in a given orientation, each hardened substantially spherical portion has an anisotropy for providing an electrical dipole moment, the electrical dipole moment rendering the hardened substantially spherical element electrically responsive such that when the hardened substantially spherical element is rotatably disposed in an electric field while the electrical dipole moment of the substantially spherical element is provided, the substantially spherical element tends to rotate to an orientation in which the electrical dipole moment aligns with the field, and

c) passing hardened substantially spherical portions through a magnetic field in substantially the same orientation with respect to the magnetic field to form magnetized substantially spherical elements wherein the magnetized segments of the plurality of substantially spherical elements are magnetized in substantially the same orientation.

18. The method of claim 1 wherein there are three planar streams.

19. The method of claim 18 wherein two planar streams contain magnetic pigment.

20. The method of claim 1 wherein there are four planar streams.

21. The method of claim 20 wherein two planar streams contain magnetic pigment.