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:
Apr. 18, 2000
Filed:
Oct. 14, 1997
John Beeteson, Ayrshire, GB;
Andrew Ramsey Knox, Ayrshire, GB;
Abstract
A magnet for use in a magnetic matrix display has a two dimensional array of apertures between opposite poles of the magnet. The direction of the magnetic field is such that the magnet generates, in each channel, a collimating magnet field for forming electrons from a cathode into an electron beam. A `keeper`, area around the periphery of the magnet is used to improve the linearity of the field strength in the apertures from apertures at the center of the magnet to apertures at the periphery of the magnet. The `keeper`, area may have control circuits placed on the surface of that area of the magnet. The keeper area may contain apertures which are not used for collimation and into which electrons are prevented from entering by a grid electrode or by a physical blocking means.