Electrophoretic display panel with tapered grid insulators and associated methods
AssigneeCopytele, Inc.
InventorsFrank J. DiSanto, Denis A. Krusos
Life of this patent
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Abstract
A triode-type electrophoretic display includes a fluid-tight envelope for containing an electrophoretic fluid with suspended pigment particles and has a glass viewing window upon which has been deposited a plurality of parallel cathode members. A plurality of elongated insulator strips are interposed between and electrically insulate the cathode members from a plurality of parallel vertical grid members. Each of the strips support a corresponding grid member thereon a selected distance from the cathode members and tapers at a least one end such that the grid member is supported by the window at that end. The window provides a stable substrate for wire bonding the grid members to display driver circuitry.
Claims24
An electrophoretic display comprising:
- (a) a fluid tight envelope having a planar portion thereof which is at least partially transparent;
- (b) an electrophoretic fluid contained within said envelope, said fluid having pigmented particles suspended therein;
- (c) a plurality of elongated substantially parallel cathode conductor members deposited upon said planar portion and contained within said envelope;
- (d) a plurality of elongated substantially parallel grid conductor members contained within said envelope, said grid conductor members and said cathode conductor members defining a matrix with a plurality of intersections, and said grid and cathode conductor members being selectively electrically chargeable to induce movement of said particles within said fluid;
- and
- (e) a plurality of elongated grid insulator strips interposed between and electrically insulating said cathode conductor members from said grid conductor members, each of said strips separating a respective grid conductor member from a corresponding cathode conductor member by a selected distance, each of said strips having a substantially planar top surface extending parallel to a base surface and an edge surface sloping downwardly from said top surface to said base surface, wherein said base surface is supported by said planar portion and a continuous surface portion of each grid conductor member is in contact with and supported by both said downwardly sloping edge surface and said planar portion.
A method for making an electrophoretic display having a glass faceplate with a plurality of elongated substantially parallel horizontal conductor members deposited thereon, a plurality of elongated substantially parallel vertical conductor members, and a plurality of elongated insulator strips interposed between and electrically insulating said horizontal members from said vertical members, said strips affixed to said horizontal members and to said vertical members and each of said strips supporting a corresponding vertical member thereon a selected distance from said horizontal members and having a substantially planar top surface extending parallel to a base surface and an edge surface sloping downwardly from said top surface to said base surface, wherein said base surface is supported by said planar portion and a continuous surface portion of each vertical conductor member is in contact with and supported by said downwardly sloping edge surface and by said faceplate, comprising the steps of:
- (a) forming said horizontal members upon a surface of said faceplate;
- (b) applying a layer of photoresist to said surface;
- (c) exposing said layer to light;
- (d) simultaneously with said step of exposing, controlling the areas of said layer exposed to light with a mask, said mask having a portion thereof which partially and graduatedly shades a selected area of photoresist to produce said downwardly sloping edge surface thereon when developed;
- (e) developing said exposed photoresist;
- (f) applying layer of conductor material on said developed photoresist;
- and
- (g) etching said conductor material and said underlying photoresist to form said vertical members and said insulator strips such that a continuous portion of each vertical member is disposed on said downwardly sloping edge surface defined by each of said corresponding insulator strips and on said faceplate.
Dependencies are inferred from the claim text.