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. 05, 1976
Filed:
Mar. 17, 1975
Karl H Loeffler, San Jose, CA (US);
Hans C Pfeiffer, Ridgefield, CT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A shielded magnetic lens and deflection yoke structure for an electron beam column which minimizes aberrations in the lens system caused by winding asymmetry in the field coil, as well as aberrations due to eddy currents created within the magnetic circuit of the lens by interaction with the field of the deflection yoke. The shield includes a polepiece structure for the magnetic electron lens generally comprising a hollow cylinder formed of a plurality of precisely machined magnetic discs stacked concentrically with precisely machined nonmagnetic discs in alternating sequence with the lens coil positioned adjacent the periphery of the cylinder and the deflection yoke positioned within the cylinder or proximate to either end thereof. In one preferred embodiment of the invention the magnetic discs are formed of a nonconductive material such as ferrite and the nonmagnetic discs are formed of alumina.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile