Electrophoretic display panel with selective character addressability
AssigneeCopytele, Inc.
InventorsChristopher A. Laspina, Edward G. Lewit
Life of this patent
Estimating the term…
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.
Claims16
In an electrophoretic display for displaying characters in a plurality of character positions of a predetermined area, wherein said display includes a cathode structure, a grid structure, an anode structure and an electrophoretic suspension disposed in between said cathode structure and said anode structure, an improved anode structure comprising:
- a substrate;
- a plurality of conductive character blocks disposed on said substrate to lie in a single plane and arranged in a matrix containing columns and rows, each of said character blocks being a single unitary solid layer of conductive material of said predetermined area, wherein each of said character blocks is separated from each other on said substrate by column spaces and row spaces that define said predetermined area of each of said character blocks, and wherein each of said character blocks corresponds in position to one of the character positions in said display;
- row control lines disposed on said substrate in each of said row spaces, wherein a single row control line is coupled to each of said character blocks in a common row in said matrix;
- column control lines disposed on said substrate in each of said column spaces, wherein a single column control line is coupled to each of said character blocks in a common column in said matrix, and;
- means for selectively applying voltage to one said row control line and one said column control line to selectively change the voltage of one of said conductive character blocks in said matrix.
A method for selectively addressing character positions of a predetermined size on an electrophoretic display having a cathode structure and a grid structure, comprising the steps of:
- providing an anode having a plurality of conductive character blocks arranged to lie in a single plane in a matrix containing columns and rows, each of said character blocks being a single unitary solid layer of conductive material of said predetermined size, wherein each of said character blocks are separate from each other and each of said character blocks correspond in size and location to one of the character positions on the display;
- interconnecting each of said character blocks in a row of said matrix with a single row control line and interconnecting each of said character blocks in a column of said matrix with a single column control line;
- and
- selectively erasing a selected character block in said matrix by applying a negative voltage to said row control line and said column control line that intersect at the selected character block.
An electrophoretic display, comprising:
- anode having a plurality of separate character blocks arranged to lie in a single plane in a matrix having columns and rows, each of said, character blocks being a single unitary solid layer of conductive material deposited on a substrate, wherein each of said character blocks is of a predetermined area that is large enough to contain the largest sized character capable of being displayed on said electrophoretic display;
- a plurality of parallel row control lines arranged in between said rows of said matrix, wherein each of said character blocks in said matrix is coupled to a single common row control line;
- a plurality of parallel column control lines perpendicular to said row control lines and arranged between said columns of said matrix, wherein each of said character blocks in each of said columns in said matrix is coupled to a single common column control line;
- a plurality of parallel cathode lines;
- a plurality of parallel grid lines perpendicular to said cathode lines and insulated therefrom so as to form an X-Y matrix, said X-Y matrix of cathode and grid lines being arranged at a distance from said anode;
- an electrophoretic dispersion of particles in a suspension medium arranged between said anode and said X-Y matrix;
- means for controlling and applying voltage to selected cathode and grid lines of the X-Y matrix so as to cause the particles in the suspension medium to migrate toward the anode to write in the character blocks;
- means for selectively applying voltage to said row and column lines to write and erase individual character blocks, said voltage applying means applying a voltage to a row and column line corresponding to the character block to be erased so that the particles in the suspension medium between said selected plurality of cathode and grid lines and one of said conductive character blocks are caused to migrate away from the anode toward the X-Y matrix;
- and
- means for integrally controlling said means for applying voltage to said X-Y matrix and said means for applying voltage to said row and column control lines.
Dependencies are inferred from the claim text.