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:
Dec. 20, 1983
Filed:
Jul. 21, 1982
Stanley E Lehnert, Addison, IL (US);
Donald Ankeny, Schaumburg, IL (US);
Zenith Radio Corporation, Glenview, IL (US);
Abstract
A system for correcting for vertical off-axis optical projection distortions in a projection television is disclosed. In a projection television wherein the image projection axis is obliquely disposed in the vertical direction relative to the projection screen axis, a system for correcting for video image distortion caused by this configuration involving modulating the vertical size input is disclosed. A vertical rate correction signal is developed from the vertical output circuit and provided in a feedback arrangement to a sawtooth wave signal generating circuit for regulating electron beam vertical sweep in a projection television CRT, or CRT's. By decreasing CRT electron beam vertical sweep rate across that portion of the projection screen where the video image is vertically stretched and increasing the vertical sweep rate for the vertically compressed portion of the video image, a linear, distortion-free image is presented on the projection screen.