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. 31, 2001
Filed:
May. 19, 1997
John Beeteson, Skelmorlie, GB;
Andrew Knox, Kilbirnie, GB;
International Business Machines Corporation, Armonk, NY (US);
Abstract
Raster demodulation apparatus for a raster-scanned cathode ray tube display comprises control means (,) for varying the shape of at least one scanned electron beam spot (,) in a direction perpendicular to scan lines of the raster. The control means (,) comprises an electro-magnet (,) for mounting on the neck of the cathode ray tube. The magnet (,) has eight pole pieces (,) spaced around the neck of the cathode ray tube (,). A winding (,) passes around each of the pole pieces (,) in succession in opposite directions so that, when an electrical current (I) is passed through the winding, adjacent pole pieces (,) around the neck of the cathode ray tube have different magnetic polarity to generate, within the neck of the cathode ray tube (,), a magnetic field in which magnetic lines of force (,) pass through the or each electron beam (,) only in a direction parallel to the scan lines of the raster.