Abstract: The present invention are dielectric black particles for use in electrophoretic images displays, electrostatic toner or the like, and the corresponding method of manufacturing the same. The present invention black particles are latex particles formed by a polymerization technique, wherein the latex particles are stained to a high degree of blackness with a metal oxide.

Abstract: An electrophoretic display having a plurality of individual characters which are individually addressable for writing and erasing. The anode of the display has a plurality of character blocks which correspond to the character positions of the display. The character blocks are interconnected by a series of character column and row control lines which are insulated from each other. Each character block is connected to one row line and one column line, respectively, by a resistor and a diode which are arranged in parallel. A further resistor is connected in series with the diode. An individual character block is erased by applying a negative voltage to the specific column line and row line which cross at the desired character block.

Abstract: A process for forming dielectric particles includes admixing a vinyl halide monomer and a crosslinker in a liquid dispersion medium to form a first mixture. A second mixture of an initiator and a stabilizer is prepared and added to the first mixture to form a third mixture in which the monomer polymerizes to form white crystalline polymer particles which are sonified for uniformity. The particles may be stained by exposure to a dehydrohalegenation reagent and dispersed in an electrophoretic fluid for use in an electrophoretic display.

Abstract: A dielectric suspension for use in an electrophoretic image display, electrostatic printing or the like, comprising a suspension medium including a dense fluorinated solvent and a less dense hydrocarbon solvent, a plurality of pigment particles dispersed in the suspension medium, a fluid dye dissolved in the suspension medium for providing a contrast with the pigment particles, and a charge control agent adsorbed on the pigment particles for preventing the pigment particles from agglomerating.

Abstract: An electrophoretic display includes a laminated triple pane construction with an electrophoretic fluid-containing envelope formed between the first and second panes and an ionizable gas-containing envelope between the second and third panes. A transparent reference electrode coats the first pane internal to the fluid envelope. A matrix of discrete pixels are disposed upon the second pane within the fluid envelope. Each pixel has a probe extending therefrom through the second pane and into the gas envelope. A plurality of row electrodes are disposed upon the second pane in the gas envelope in close proximity to corresponding rows of probes. A plurality of column electrodes disposed upon the third pane within the gas envelope perpendicular to the row lines establishes an addressable X-Y matrix. By impressing a sufficient voltage differential at selected intersections of the matrix, a local ionization of gas biases a proximate probe to the ionization potential.

Abstract: The present invention is a modular electrophoretic display that can be selectively attached or detached from a larger assembly. The modular electrophoretic display includes a small, low voltage battery that provides a small bias to the anode, cathode and grid electrode of the electrophoretic display when no other power is present. As a result of the bias of the battery, the electrophoretic display is capable of retaining any image formed upon the display by the larger assembly. Consequently, different displays with differing images can be removed from, or added to, the larger assembly as needed. This promotes ease in photocopying the electrophoretic display and enables the display to be mailed, stored or otherwise handled without the loss of the image.

Abstract: Method for operating an electrophoretic display panel in a hold mode that reduces power required, increases display life and improves performance which entails applying a voltage to the anode electrode structure during the "hold" mode of operation which is substantially lower in amplitude than the voltage applied to the anode structure during a "write" mode of operation.

Abstract: A process for forming dielectric particles includes admixing a vinyl halide monomer and a crosslinker in a liquid dispersion medium to form a first mixture. A second mixture of an initiator and a stabilizer is prepared and added to the first mixture to form a third mixture in which the monomer polymerizes to form white crystalline polymer particles which are sonified for uniformity. The particles may be stained by exposure to a dehydrohalegenation reagent and dispersed in an electrophoretic fluid for use in an electrophoretic display.

Abstract: An electrophoretic display includes a plurality of groups of intersecting row and column electrodes, and a plurality of parallel anode electrode segments disposed in spaced relation within a fluid-tight envelope containing a suspension of pigment particles in a dielectric fluid. Each respective group of row and column electrodes and a corresponding anode segment are indicative of a character line of displayed text. The display includes a line control system operable in a partial erase mode to partially erase a character line having a character thereof selected for erasure and operable in a rewriting mode to rewrite to the character line all characters not selected for erasure. The line control system is operable to alternate sequentially between the two modes until the selected character is simply erased or replaced entirely with a new character.

Abstract: An electrophoretic display has a grid cathode matrix arrangement consisting of a first plurality of parallel conductive lines insulated from a second plurality of parallel conductive lines transverse to said first plurality. Located with respect to the grid and cathode lines are first and second anode structures. The first anode is remote from the second with the second anode overlying the gird lines of the display and insulated therefrom. The second anode is biased to implement typical HOLD and ERASE modes independent of the first anode.

Abstract: There is disclosed a telephone subset which incorporates a high resolution electrophoretic display on the surface of a subset housing. The telephone subset includes a microprocessor which operates under the control of a mode selector. In this manner the display is employed to generate various keyboard formats and operates in conjunction with a position sensitive overlay to enable a subscriber to place telephone calls in a conventional manner when the keyboard display is implemented on the electrophoretic display. The telephone subset in conjunction with various subset buttons which control the mode selector is capable of operating in different modes. Due to the high resolution and large capacity of the display one can now present pages of stored telephone numbers which essentially enables a user to select any number by means of a movable cursor and by pressing another subset button can immediately dial that number.

Abstract: A telephone subset which incorporates a high resolution electrophoretic display on the surface of a subset housing. The telephone subset includes a microprocessor which operates under the control of a mode selector. In this manner the display is employed to generate various keyboard formats and operates in conjunction with a position sensitive overlay to enable a subscriber to place telephone calls in a conventional manner when the keyboard display is implemented on the electrophoretic display. The telephone subset in conjunction with various subset buttons which control the mode selector is capable of operating in different modes. Due to the high resolution and large capacity of the display one can now present pages of stored telephone numbers which essentially enables a user to select any number by means of a movable cursor and by pressing another subset button can immediately dial that number.

Abstract: A tetrode type electrophoretic display includes local anode lines electrically grouped into groups having the width of a character. In operation, the local anode may be used to blink selected characters by applying appropriate voltages to the various electrodes of the display in the proper sequence. Sequencing is controlled by a computer and associated software.

Abstract: An electrophoretic suspension prepared in accordance with the present invention comprises a dielectric fluid having suspended therein a plurality of pigment particles movable between the electrodes of an EPID device in response to an electric potential applied thereto and an effective amount of at least one additive for chemically absorbing at least one gas in the fluid. To absorb hydrogen gas in the dielectric fluid, a hydrogen absorbing additive is dispersed therein. The molecule of the hydrogen absorbing additive has an aromatic C/H ratio of 1/0.8 or less, and preferably between 1/0.67 and 1/0.75. To absorb chlorine gas in the dielectric fluid, an effective amount of an chlorine gas absorbing compound is also preferably added thereto. The chlorine gas absorbing additive comprises a molecule having at least one double bond and may be a sterically strained alkene such 5-ethylidene-2-norbornene.

Abstract: The invention provides an electrophoretic suspension comprising a suspension medium including tetrachloroethylene, 5-ethylidene-2-norbornene and an aromatic solvent including either a mixture of phenyl xylyl ethanes or a mixture of mono and di-benzyl toluene. The suspension further comprises a plurality of pigment particles dispersed in the suspension medium; a fluid dye dissolved in the suspension medium for providing a contrast with the pigment particles; and a charge control agent adsorbed on the pigment particles for preventing the pigment particles from agglomerating.

Abstract: An electrophoretic display includes a laminated triple pane construction with an electrophoretic fluid-containing envelope formed between the first and second panes and an ionizable gas-containing envelope between the second and third panes. A transparent reference electrode coats the first pane internal to the fluid envelope. A matrix of discrete pixels are disposed upon the second pane within the fluid envelope. Each pixel has a probe extending therefrom through the second pane and into the gas envelope. A plurality of row electrodes are disposed upon the second pane in the gas envelope in close proximity to corresponding rows of probes. A plurality of column electrodes disposed upon the third pane within the gas envelope perpendicular to the row lines establishes an addressable X-Y matrix. By impressing a sufficient voltage differential at selected intersections of the matrix, a local ionization of gas biases a proximate probe to the ionization potential.

Abstract: The invention provides a working fluid for an electrophoretic image display device including a dispersion of finely divided diarylide yellow pigment particles each having a charge of a given polarity and acidic hydrogen surface sites in a suspension medium. Each of the pigment particles are transportable within the suspension medium, under the influence of an electric field, toward or away from at least one transparent plate. Adsorbed on the surface of each pigment particle is a thin layer of a charge control agent having a polyisobutylene chain and a basic anchoring group which reacts with the acidic surface sites to form charge pairs therewith. The polyisobutylene chains extend from the pigment surfaces on which the charge control agent is adsorbed, thereby providing a steric barrier between pigments and preventing agglomeration. The specific gravity of the suspension medium is matched with that of the pigment particles by combining effective amounts of secondary butyl benzene and tetrachloroethylene.

Abstract: A process for forming dielectric particles includes admixing a vinyl halide monomer and a crosslinker in a liquid dispersion medium to form a first mixture. A second mixture of an initiator and a stabilizer is prepared and added to the first mixture to form a third mixture in which the monomer polymerizes to form white crystalline polymer particles which are sonified for uniformity. The particles may be stained by exposure to a dehydrohalegenation reagent and dispersed in an electrophoretic fluid for use in an electrophoretic display.

Abstract: A tetrode type electrophoretic display includes local anode lines electrically grouped into groups having the width of a character. In operation, the local anode may be used to blink selected characters by applying appropriate voltages to the various electrodes of the display in the proper sequence. Sequencing is controlled by a computer and associated software.