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:
Feb. 13, 1990
Filed:
Aug. 19, 1988
Philip J Bos, Portland, OR (US);
Tektronix, Inc., Beaverton, OR (US);
Abstract
A liquid crystal cell (10) includes a chiral liquid crystal material (16) captured between a pair of electrode structures (12 and 14). The liquid crystal material is of a type that exhibits in consecutive order chiral semitic nematic, smectic A, and chiral phases at successively lower temperatures. In a preferred embodiment, the chiral phase is of the smectic C type. The electrode structures have director alignment layers (22 and 22') deposited on their inner surfaces. The directors (28 and 30) of the liquid crystal material in the nematic phase in contact the alignment layers align at relatively large tilt bias angles relative to the alignment layer. The tilt bias angles of the directors in contact with one of the electrode structures are defined in a rotational sense which is opposite that of the tilt bias angles of the directors in contact with the other electrode structure. The liquid crystal cell of the present invention is substantially free from smectic plane alignment defects and exhibits substantially uniform director alignment properties. As a consequence, a display device (36) using the liquid crystal cell has an essentially contaminant-free viewing surface and good light extinction properties. Such a display device also has a relatively large off-axis viewing angle.