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:
Jun. 16, 1981
Filed:
Jan. 08, 1980
Stanley E Lehnert, Addison, IL (US);
Zenith Radio Corporation, Glenview, IL (US);
Abstract
Means and method are disclosed for compensating for non-linear magnification distortion in projection television systems. The projection television system has a projection screen for displaying a light image cast thereon. The screen is spaced apart from at least one light projection means whose projection optical axis lies at a non-zero, acute-angle A with respect to the screen axis. The light projection means comprises cathode ray tube means having a cathodoluminescent screen on the inside surface of a face panel thereof whose axis is substantially parallel to the projection optical axis. Electron-beam generating means are disposed on the cathode ray tube electron-optical axis for forming an electron image on the cathodoluminescent screen which is converted to a visible image by the cathodoluminescent screen. Lens means on the projection optical axis provide for projecting on the projection screen the light image of the electron-formed visible image. The light image inherently has non-linear magnification distortion attributable to the location of the projection means off the projection screen axis. The system is characterized according to one embodiment of the invention by the cathode ray tube electron-optical axis defining a non-zero, acute-angle B with respect to the axis of the cathodoluminescent screen. The value of the angle B and the orientation of the electron optical axis is selected according to the invention to cause the electron-formed visible image to have an orientation and a non-linear magnification distortion effective to substantially compensate for the off-axis-induced non-linear magnification distortion of the projected light image.