Internal masking layer to prevent parallax in an electro-optical display or indicator unit

US4552437A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Karl Gantenbrink · Karlsruhe, DE
• Peter Knoll · Ettlingen, DE
• Peter Rapps · Karlsruhe, DE

Key dates

• Filing date: Oct 7, 1983
• Grant date: Nov 12, 1985
• Expiry date: Oct 7, 2003

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S359/90
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

To prevent parallax distortion, and to simplify application of masking patterns, particularly for LCD units, the mask is applied to the front-, or back-plate electrode at the side facing the liquid crystal, and opposite the interrupted, or etched front-plate electrode on the back support plate. Suitable methods are printing, particularly with a coarse or rough grain lacquer varnish or ink, the projections of the coarse grain forming the microspacers between said plates and for retaining the liquid crystal medium; other methods are galvanic deposition on the continuous electrode, and selected exposure of photographic emulsions, particularly color emulsions so that, with multi-color emulsions, multi-color effects can be obtained although only a single thickness of emulsion layer is applied.