The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 04, 2000
Filed:
Nov. 17, 1997
Jurg Funfschilling, Basel, CH;
Martin Schadt, Seltisberg, CH;
Rolic AG, Zug, CH;
Abstract
Known liquid crystal cells have a nematic liquid crystal configuration and, in accordance with this configuration, are referred to as TN or STN cells. It is true that such cells are adequate for many applications. However, their image quality is dependent to a very great extent on the user's angle of view. Furthermore, TN and STN cells require a continuously applied signal voltage if it is intended to display or store information on one. Bistable liquid crystal cells having a ferroelectric, chiral smectic liquid crystal layer do not have these disadvantages of nematic display cells. However, the commercial production of such bistable display cells has scarcely become established to date. This is in particular because they are not very suitable for reliably storing information or do not permit absolutely equivalent switching between the two bistable positions of the director. The invention now proposes a novel, bistable liquid crystal cell which avoids precisely these disadvantages. Starting from the SBFLC display cell disclosed in EP-A 0 405 346, the display cell according to the invention is distinguished in that its liquid crystal layer contains polymerized molecules and is formed, by treatment with light and an alternating electric field, in such a way that it has two equivalent, bistable switching states.