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:
Feb. 03, 1987
Filed:
Jan. 03, 1986
Applicant:
Inventors:
Shinpei Koshigoe, Fukaya, JP;
Takeshi Fujiwara, Fukaya, JP;
Assignee:
Tokyo Shibaura Denki Kabushiki Kaisha, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01J / ; H01J / ;
U.S. Cl.
CPC ...
313449 ; 313414 ;
Abstract
An electron gun is proposed which has a cathode for generating an electron beam and at least three grids, each having an opening. A pre-focusing electron lens and a main focusing electron lens are formed between the grids in the order named from the cathode to the grids. The pre-focusing lens constitutes a first asymmetric electron lens. The main focusing electron lens constitutes a second asymmetric electron lens. The first and second asymmetric electron lenses have focusing actions whose relatively stronger components are effected along directions substantially perpendicular to each other.