Optical devices with switchable particles

• US 9,482,861 B2
• Filed: 10/21/2011
• Issued: 11/01/2016
• Est. Priority Date: 10/22/2010
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Lahann, Joerg, Hwang, Sang-yeul, Yoon, Jaewon, Bhaskar, Srijanani, Lee, Kyungjin, Park, Tae-Hong
• Primary Examiner(s): Martinez, Joseph P
• Assistant Examiner(s): Thomas, Brandi
• Application Number:
  US13/880,826
• Publication Number:
  US 20130329275A1
• Time in Patent Office: 1,838 Days
• Field of Search: 359/237, 359/242, 359/246, 359/247, 359290-292, 359/295, 359/296, 359/298
• US Class Current: 1/1
• 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: G02F 1/09 based on magneto-optical elements, e.g. exhibiting Faraday effect
• CPC Class Codes: G09F 9/375 the position of the elements being controlled by the application of a magnetic field

Abstract

Optical display devices and methods of operating such devices are provided. The optical device includes a display component having a plurality of anisotropic multiphasic particles with at least two optically distinct phases. The plurality of anisotropic multiphasic particles is disposed in one or more regions of the display component that define an optic feature. Further, at least one of the phases of the anisotropic multiphasic particle comprises a material receptive to a force field, such as a magnetic material is receptive to an applied magnetic field. In this manner, the display component can reversibly exhibit a first optical state in the presence of the force field and thus is optionally switchable.

Claims

1. A magnetically switchable optical device comprising:

a display component that defines an optic feature and comprises a housing having a first side, a second opposite side, and an interior comprising a plurality of anisotropic multiphasic particles, each respective anisotropic multiphasic particle comprising a first phase and at least one additional phase distinct from the first phase, wherein the first phase comprises a first colorant so that the anisotropic multiphasic particle has optically distinct phases and at least one of the first phase or the at least one additional phase comprises a magnetic material receptive to a magnetic field; and

a magnetic field generator comprising a magnet disposed external to the housing, wherein the magnet has a non-pole surface that is translatable from a first position adjacent to the first side of the housing of the display component for inducing orientation of the plurality of anisotropic multiphasic particles in a first optical state to a second position adjacent to the second opposite side for inducing orientation of the plurality of anisotropic multiphasic particles to a second optical state distinct from the first optical state.

2. The optical device of claim 1, wherein the at least one additional phase comprises a second colorant distinct from the first colorant.

3. The optical device of claim 2, wherein the at least one additional phase further comprises a second phase and a third phase, wherein the second phase comprises the second colorant, and the third phase comprises a third colorant, wherein the first, second, and third colorants are distinct from one another.

4. The optical device of claim 1, wherein the housing has at least one optically transparent wall, wherein the housing further contains a plurality of layers, wherein the optic feature is formed in at least one of the plurality of layers.

5. The optical device of claim 1, wherein the anisotropic multiphasic particle has a shape selected from the group consisting of:

spheres, rectangles, polygons, disks, ellipsoids, toroids, cones, pyramids, rods, cylinders, beads-on-a-string, and fibers.

6. The optical device of claim 1, wherein the first colorant is selected from the group of materials consisting of:

a low-molecular weight dye, a laser dye, a textile dye, a paint dye, a paint pigment, a coating dye, a coating pigment, a plastic colorant, a metal colorant, a ceramic colorant, a fluorescent dye, a phosphorescent dye, a natural dye, a polymeric dye, an inorganic pigment, an organic pigment, and combinations thereof.

7. A magnetically switchable optical device comprising:

a display component that defines an optic feature and comprises a housing having a first side, a second opposite side, and an interior comprising a suspension of a plurality of anisotropic multiphasic particle having a shape selected from the group consisting of;

rods, cylinders, and fibers, each respective anisotropic multiphasic particle comprising a first phase and at least one additional phase distinct from the first phase, wherein the first phase comprises a first colorant and the at least one additional phase comprises a second colorant, so that the anisotropic multiphasic particle has optically distinct phases and at least one of the first phase or the at least one additional phase comprises a magnetic material receptive to a magnetic field; and

a magnetic field generator comprising a magnet disposed external to the housing, wherein the magnet has a non-pole surface that is translatable from a first position adjacent to the first side of the housing of the display component for inducing a first optical state by synchronizing the position of the plurality of anisotropic multiphasic particles via magnetophoresis to a second position adjacent to the second opposite side for inducing a second optical state distinct from the first optical state via magnetophoresis.

8. The magnetically switchable optical device of claim 7, wherein the at least one additional phase comprises a second colorant distinct from the first colorant.

9. The magnetically switchable optical device of claim 7, wherein the magnet is a permanent magnet that generates and transmits a magnetic field to the housing of the display component.

10. The magnetically switchable optical device of claim 7, wherein the housing has at least one optically transparent wall, wherein the housing further contains a plurality of layers, wherein the optic feature is formed in at least one of the plurality of layers.

11. The magnetically switchable optical device of claim 7, wherein the anisotropic multiphasic particle of the plurality of anisotropic multiphasic particles is a first anisotropic multiphasic particle and the plurality of anisotropic multiphasic particles further comprises at least one additional optically distinct anisotropic multiphasic particle also comprising a magnetic material receptive to the magnetic force field.

12. The magnetically switchable optical device of claim 11, wherein the at least one additional distinct anisotropic multiphasic particle comprises a phase having a third colorant distinct from the first colorant and the second colorant.

13. The magnetically switchable optical device of claim 7, wherein the first colorant comprises a material selected from a low-molecular weight dye, a laser dye, a textile dye, a paint dye, a paint pigment, a coating dye, a coating pigment, a plastic colorant, a metal colorant, a ceramic colorant, a fluorescent dye, a phosphorescent dye, a natural dye, a polymeric dye, an inorganic pigment and/or an organic pigment.