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:
Jul. 16, 1985
Filed:
Nov. 10, 1982
Applicant:
Inventors:
Cyril Hilsum, Malvern, GB;
Edward P Raynes, Malvern, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06F / ; G09G / ;
U.S. Cl.
CPC ...
3403 / ; 200D / ; 340712 ; 340784 ; 340765 ;
Abstract
A touch sensitive switch with a liquid crystal cell and a circuit for measuring capacitive changes when the cell is deformed by touch. The cell has a layer of a liquid crystal material between slides bearing electrodes. Capacitive changes are detected for example by a comparator or by a bridge circuit which includes one or more cells. Touching one cell unbalances the bridge. The area of cell that is touched may be coincident with or separate from a display area. For some types of cells extra sensitivity is achieved by maintaining a voltage across the cell between a critical and saturation value.