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. 22, 2002
Filed:
Jan. 31, 2001
Osamu Ono, Fukaya, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
The cathode ray tube apparatus comprises a main lens constructed by focus, intermediate, and final acceleration electrodes. The main lens includes a focusing area positioned in a side of the focus electrode, and a diverging area positioned in a side of the final acceleration electrode. A focusing force curve expressing the focusing force along the tube-axis direction in the focusing area has two convex parts respectively being at first and second levels, and a concave part provided between the convex parts and being at a third level sufficiently lower than the first and second levels. The third level is set to a lowermost level at which a focusing or diverging force is not substantially effected on the electron beam. An intermediate electrode having a non-circular shaped hole is positioned near an area of the lowermost level.