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.

Abstract: A gyricon or twisting-ball display in which optically anisotropic particles, such as bichromal balls, are disposed directly in a working fluid, such as a dielectric liquid, without an elastomer substrate or other cavity-containing matrix. The display apparatus has an optically transmissive viewing surface, behind which the working fluid is disposed with the particles in it. The particles are arranged in a closely packed stable arrangement in which neighboring particles tend to keep one another in place. For example, the particles can be arranged in a hexagonally packed monolayer. The working fluid does not substantially constrain the particles to remain in the stable arrangement, notwithstanding the direct contact of the fluid with the particles.

Abstract: A gyricon or rotating-particle display having an "eggcrate" substrate. The display includes a substrate having a cavity-containing matrix whose cavities are disposed substantially in a single layer and are arranged within the matrix substantially in a geometrically regular pattern, and a plurality of optically anisotropic particles disposed in the cavities in the substrate, with each cavity containing at most one of the optically anistropic particles. A rotatable disposition of each particle is achievable while the particle is thus disposed in the substrate; the particle, when in its rotatable disposition, is not attached to the substrate.

Abstract: A gyricon or twisting-ball display having superior reflectance characteristics comparing favorably with those of white paper. The display is based on a material made up of optically anisotropic particles, such as bichromal balls, disposed in a substrate having a surface. The particles situated closest to the substrate surface form substantially a single layer. Each particle in the layer has a center point, 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 has a projected area with respect to the substrate surface. Particles of the set are 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.

Abstract: A gyricon or twisting-ball display having superior reflectance characteristics comparing favorably with those of white paper. The display is based on a material made up of optically anisotropic particles, such as bichromal balls, disposed substantially in a monolayer in a substrate. The particles are closely packed with respect to one another in the monolayer, preferably so that adjacent particle surfaces are as close to one another as possible. 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.

Abstract: An apparatus for fabricating hemispherically bichromal balls, comprising a separator member having opposing first and second surfaces located and an edge region in contact with both surfaces, and delivery means for flowing first and second colored hardenable liquid material over the first and second surfaces, respectively, so that the liquid materials arrive at the edge at substantially the same flow rate and form a reservoir outboard of the edge region. The reservoir comprises side-by-side regions of different colors which do not intermix. Further means is provided for propelling the first and second liquid materials away from the separator member and out of the reservoir into a fluid medium as a plurality of side-by-side bichromal streams whose forward ends become unstable and break up into droplets which form into spherical balls, each of the balls comprising hemispheres of differently colored hardenable liquid, and means for collecting the bichromal balls.

Abstract: Disclosed are ionographic imaging apparatuses and processes. One apparatus comprises an imaging means, means for applying to the imaging means a liquid material capable of forming a dielectric peel layer adhering to the imaging means, ionographic writing means for generating a latent image on the peel layer, means for developing the latent image on the peel layer, and means for simultaneously transferring the peel layer bearing the developed image from the imaging means to a substrate and affixing the peel layer bearing the developed image to the substrate.

Abstract: An externally stimulated continuous stream ink jet printer which suppresses or controls the formation of satellite droplets so that they are not charged differently from the main droplets. Thus, when the two are merged, indeterminate charges are not produced which would impact the print quality of the printer. The satellites are suppressed by impressing on the printer ink streams a combination of time-varying pressures. In one embodiment, the time-varying pressures are generated by two time-varying voltages applied to the EHD electrodes. One pressure has a fundamental frequency with the second pressure having a second harmonic frequency, these two pressures having a predetermined phase and amplitudes with respect to each other. The fundamental frequency is selected for a required drop spacing to stream diameter ratio.

Abstract: Apparatus for pumping charged fluid or charged particles by means of a travelling electric field which acts on the charge through Coulombic forces. The electric field is produced by a single phase time varying voltage applied to material with dimensions or electrical properties which vary in space. This material is placed between the medium to be pumped and an electrical conductor attached to the voltage supply.

Abstract: An ink jet printing system is disclosed of the type wherein selected droplets from a continuous stream of droplets are charged and deflected toward a target. The droplet placement on the target is determined by the amount of charge. The system uses an electrohydrodynamic (EHD) exciter to generate the continuous stream. The exciter is composed of one, two, three or more pump electrodes of a length equal to about one half the droplet spacing. The multiple pump electrode embodiments are spaced at intervals of multiples of about one half the droplet spacing or wavelength.