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:
Nov. 30, 1999
Filed:
Jan. 30, 1998
Applicant:
Inventors:
Hirofumi Ueno, Fukaya, JP;
Tsutomu Takekawa, Fukaya, JP;
Assignee:
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
313413 ; 313412 ; 313414 ;
Abstract
An electron gun comprises a supplementary grid applied with a voltage which dynamically changes in synchronization with a magnetic field generated by a deflection yoke, between a second grid and a third grid. Further, by the second grid, the supplementary grid, and the third grid, an electron is constructed which has an astigmatic aberration in which a focusing force in the horizontal direction is stronger than a focusing force in the vertical direction. The intensity of the astigmatic aberration of the electron lens is dynamically changed by a voltage applied to the supplementary grid.