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:
Aug. 21, 1990
Filed:
Dec. 13, 1988
John L Beiswenger, Salem, WI (US);
Technomarket, Inc., Buffalo Grove, IL (US);
Abstract
An apparatus for providing a control signal includes a liquid crystal panel with means for transiently forming transparent windows therein. There is a source of electromagnetic radiation (EMR) adjacent one side of the panel and positioned to pass EMR through a first set of transiently open windows adjacent thereto. There is an EMR detector positioned adjacent an opposite side of the panel and positioned to detect EMR from the source which has passed through one or more of the first set of transiently open windows and which has also passed through one or more of a second set of transiently open windows positioned adjacent the detector. There is a timing and logic circuit which correlates the opening of windows in the first set and in the second set whereby an EMR occluding object may be located relative to mutually perpendicular axes, one of which is parallel to both the first and second set of transiently open windows, the location of said occluding object providing a control signal representative thereof.