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. 09, 2002
Filed:
Oct. 04, 1999
Roger Casanova Alig, Princeton Junction, NJ (US);
Dennis John Bechis, Yardley, PA (US);
Sarnoff Corporation, Princeton, NJ (US);
Abstract
A projection tube has a phosphor-coated faceplate at one end of a vacuum envelope and a plural-beam providing electron lens structure at the opposite end thereof. The electron lens structure includes four electrodes having axially-aligned apertures defining parallel channels for the plural electron beams to pass through to be focused and converged onto a small spot on the faceplate. The first and second electrodes of the electron lens structure shape the electron beams and the third and fourth electrodes thereof converge and focus the electron beams toward the same location on the faceplate. The potential applied to the fourth electrode is at or close to the potential at the phosphor, and is substantially higher than the potential applied to the third electrode. The lens structures of the third and fourth electrodes may each include an inner electron lens structure and an outer electron lens structure. The lens structure of the invention provides a projection tube having greater brightness and/or smaller spot size than is conventionally available.