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:
Apr. 08, 1986
Filed:
Dec. 10, 1982
Shoji Shirai, Koganei, JP;
Masaaki Yamauchi, Togane, JP;
Kazuo Majima, Mobara, JP;
Hiroshi Takano, Hachioji, JP;
Masakazu Fukushima, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electron gun used in a color picture tube having means for emitting three electron beams toward the fluorescent screen, and main lenses for focusing the electron beams on the fluorescent screen. The main lenses are constituted by two envelopes spaced out from each other and adapted to surround the electron beams, and two electrode plates located on the confronting end surfaces of the envelopes and provided with three apertures aligning on a line for conducting the three electron beams. At least one of the two electrode plates is recessed relative to another electrode plate and disposed inside the envelope, and the recessed electrode plate is structured such that non-rotational symmetry of the lens caused by the recess of the electrode is corrected.