Method of making a twisting ball panel display

• US 4,143,103 A
• Filed: 05/04/1976
• Issued: 03/06/1979
• Est. Priority Date: 05/04/1976
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Sheridon, Nicholas K.
• Primary Examiner(s): Arnold, Donald J.
• Application Number:
  US05/683,436
• Time in Patent Office: 1,036 Days
• Field of Search: 264/1, 264/4, 264/232, 264/7, 264/343, 264/347, 264/109
• US Class Current: 264/4
• 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 1/172 based on a suspension of orientable dipolar particles, e.g. suspended particles displays
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field

Abstract

A method of making a display characterized by a plurality of particles which have an electrical anisotropy due to hemispherical surface coatings of different Zeta potential and their distribution in a volume of a dielectric liquid and which also have an optical anisotropy due to the hemispherical surface coatings having different optical characteristics. The particles are mixed with a light transparent liquid which is subsequently cured to form an elastomeric or rigid slab. Following curing of the liquid, the slab is emersed in a plasticizer (dielectric liquid) which is absorbed by the slab and which causes the slab to expand slightly. Expansion of the slab around the particles provides a plasticizer-filled cavity around each particle which cavities allow the particles to rotate to provide a display in accordance with their optical anisotropy but does not allow substantial translation of the particles.

Claims

1. A method of making an optical display panel comprising the steps of:

thoroughly mixing a plurality of solid, optically anisotropic particles with a non-solid material capable of being cured to a solid state to provide a mixture of said particles and said material,

curing said mixture to solidify said material whereby said particles are trapped within a slab of said material, and

dispersing said slab with said particles trapped therein into a bath of a dielectric plasticizer which is absorbed more readily by said solidified material than by said particles whereby said solidified material swells to create plasticizer-filled voids around said particles such that said particles can have rotational movement but substantially no translational movement within said slab.

2. The method of claim 1 wherein said material is an elastomer.

4. The method of claim 1 wherein a portion of the surface of each of said optically anisotropic particles are coated with a light reflective material, the remaining portion of said surface being coated with a light absorptive material.

3. A method of making an optical display panel comprising the steps of:

thoroughly mixing a plurality of solid, optically anisotropic particles with an uncured elastomer to provide a mixture of said particles and said elastomer,

heat curing said mixture to solidify said elastomer whereby said particles are trapped within said elastomer, and

dispersing said solidified elastomer with said particles trapped therein into a bath of a dielectric plasticizer which is absorbed more readily by said elastomer than by said particles whereby said elastomer swells to create plasticizer-filled voids around said particles such that said particles can have rotational movement but substantially no translational movement.

5. The method as defined in claim 3 wherein a portion of the surface of each of said optically anisotropic particles are coated with a light reflective material, the remaining portion of said surface being coated with a light absorptive material.