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:
Oct. 20, 1987
Filed:
Aug. 23, 1985
James P Beasley, Tadworth, GB;
U.S. Philips Corporation, New York, NY (US);
Abstract
An apparatus, such as an electron beam column (1), with high-speed deflection capability comprises a gun (2) which directs a beam (3) of charged particles by several magnetic lenses (9,11,13a,13b) towards a target (4). Magnetic deflection coils (12a,12b) produce a variable magnetic field for controllably deflecting the beam. The beam is surrounded by an electrically conductive surface (16a,16b,22) which in the vicinity of the deflection coils is constituted by a tube (22) comprising a single wire of, for example, nichrome preferably coated by an oxide film formed naturally and comprising a close-wound helix. This tube construction has a longitudinal resistance which significantly impedes the flow of undesirable eddy currents therein. On the other hand the tube can readily conduct along a helical path so that charge accumulation on the tube walls is avoided.