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. 01, 1976
Filed:
Mar. 04, 1975
Thomas J Ray, Yonkers, NY (US);
Thomas J Rebeschi, North Haven, CT (US);
United Technologies Corporation, Hartford, CT (US);
Abstract
A cathode ray tube employing magnetic deflection coils for deflecting the electron beam in the horizontal and vertical directions, is corrected for the astigmatism error created by the non-uniform magnetic deflection field which causes a predictable elliptical distortion of the electron beam, through the use of two sets of correction coils mounted on a common annular magnetic core located on the neck of the CRT, which distorts the electron beam prior to its entry into the magnetic deflection field in a manner that is complementary to the distortion created by the non-uniform magnetic deflection field. The excitation currents for the correction coils are derived from the horizontal (Vx) and vertical (Vy) beam deflection voltage signals, in such a manner that the excitation current for the first correction coil is proportional to Vx.sup.2 - Vy.sup.2, and the excitation for the second correction coil is proportional to 2.sup.. Vx.sup.. Vy.