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:
Jan. 29, 1991
Filed:
Jan. 08, 1990
Tjerk G Spanjer, Eindhoven, NL;
Gerardus A Vrijssen, Eindhoven, NL;
Willem M Van Alphen, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
Picture display device comprising a display tube having an electron gun with an electrostatic focusing lens for generating a focusing lens field, which tube further comprises deflection means for generating a deflection field. The focusing lens field partly overlaps the deflection field. The focusing lens comprises a tubular structure having an inner surface on which a helical resistance structure of a material having a high electrical resistance is provided, which tubular structure has a coaxial input portion and a coaxial output portion, the output portion having dimensions which prevent the deflected electron beam from impinging upon the glass of the inner wall. Correction means may be provided for correcting errors caused by the advanced position of the focusing lens.