Gyricon display with interstitially packed particles
First Claim
1. A material comprising:
- a substrate; and
a plurality of optically anisotropic particles disposed in the substrate, the plurality of particles including first and second populations of particles,the particles of the first population as considered by themselves without the particles of the second population being disposed in the substrate in a closely packed arrangement having interstices,the particles of the second population being disposed in the interstices of the arrangement,a rotatable disposition of each particle of the plurality being achievable while said particle is thus disposed in the substrate, said particle, when in said rotatable disposition, not being attached to the substrate.
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Accused Products
Abstract
A gyricon or twisting-ball display having superior reflectance characteristics comparing favorably with those of white paper is based on a material made up of two populations (e.g., two different sizes) of optically anisotropic particles, such as bichromal balls, disposed in a substrate. Particles of the first population, as considered by themselves without the particles of the second population, are disposed in the substrate in a closely packed (e.g., geometrically regular) arrangement having interstices. Particles of the second population are disposed in the interstices of the arrangement. A rotatable disposition of each particle is achievable while the particle is thus disposed in the substrate; for example, the particles can already be rotatable in the substrate, or can be rendered rotatable in the substrate by a nondestructive operation performed on the substrate. In particular, the particles can be situated in an elastomer substrate that is expanded by application of a fluid thereto so as to render the particles rotatable therein. A particle, when in its rotatable disposition, is not attached to the substrate. A reflective-mode display apparatus can be constructed from a piece of the material together with a mechanism (e.g., addressing electrodes) for facilitating rotation of at least one of the particles.
126 Citations
27 Claims
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1. A material comprising:
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a substrate; and a plurality of optically anisotropic particles disposed in the substrate, the plurality of particles including first and second populations of particles, the particles of the first population as considered by themselves without the particles of the second population being disposed in the substrate in a closely packed arrangement having interstices, the particles of the second population being disposed in the interstices of the arrangement, a rotatable disposition of each particle of the plurality being achievable while said particle is thus disposed in the substrate, said particle, when in said rotatable disposition, not being attached to the substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. Apparatus comprising:
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a member having an optically transmissive viewing surface; a plurality of optically anisotropic particles rotatably disposed behind the viewing surface with respect to an observer situated favorably to observe the viewing surface, at least some of the particles thus being observable by the observer through the viewing surface, each particle of the plurality having an anisotropy for providing an electrical dipole moment, the electrical dipole moment rendering the particle electrically responsive such that when the particle is rotatably disposed in an electric field while the electrical dipole moment of the particle is provided, the particle tends to rotate to an orientation in which the electrical dipole moment aligns with the field, the plurality of particles including first and second populations of particles, the particles of the first population as considered by themselves without the particles of the second population being disposed in an arrangement having interstices, the particles of the second population being disposed in the interstices of the arrangement; means for keeping in place with respect to the viewing surface the particles of the plurality thus disposed; and means for facilitating a rotation of at least one of the particles of the plurality thus disposed by selectively applying an electric field to a particle for which the electrical dipole moment is provided. - View Dependent Claims (24, 25)
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26. A material comprising:
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a substrate; and a plurality of optically anisotropic particles disposed in the substrate, the plurality of particles including first and second populations of particles, the particles of the first population being of a substantially uniform first size characterized by a first linear dimension, the particles of the second population being of a substantially uniform second size characterized by a second linear dimension less than the first linear dimension, the particles of the first and second populations having similar optical anisotropies, a rotatable disposition of each particle of the plurality being achievable while said particle is thus disposed in the substrate, said particle, when in said rotatable disposition, not being attached to the substrate.
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27. A material comprising:
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a substrate having an optically transmissive surface, the surface having an area; and a plurality of optically anisotropic particles disposed in the substrate, the plurality of particles including first and second populations of particles, the particles of the first population as considered by themselves without the particles of the second population being disposed in the substrate in an arrangement comprising substantially a single layer of particles, the layer being formed of those particles situated closest to the substrate surface among all the particles of the first population, each particle in the layer having a center point, substantially no particle in the layer being disposed entirely behind the center point of any nearest neighboring particle in the layer with respect to the substrate surface, each particle in the layer having a projected area with respect to the substrate surface, the particles of the layer being sufficiently closely packed with respect to one another in the layer that the union of their projected areas exceeds two-thirds of the area of the substrate surface, the particles of the second population being situated amidst the particles of the first population such that light incident on a portion of the substrate and transmitted therethrough towards the particles of the plurality in a vicinity of said portion illuminates and is modulated by particles of both populations in said vicinity, the particles of the second population in said vicinity thus modulating light that would otherwise, but for the presence of the particles of the second population, pass through the layer by passing between particles of the first population.
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Specification