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:
Aug. 10, 1993
Filed:
Sep. 08, 1992
Charles A Spindt, Menlo Park, CA (US);
Innovative Display Development Partners, Fremont, CA (US);
Abstract
An arrangement for and method of automatically collimating an expanding electron beam emitted from a field emission cathode is disclosed herein. This is accomplished without an externally powered colimating or focusing electrode. Rather, a dielectric member is positioned around the path taken by the beam so that when the beam is initially turned on, it bombards the dielectric member with free electrons and thereby places a negative electrostatic charge, ultimately reaching the potential of the cathode electrode itself, on the dielectric member. This electrostatic charge, in turn, causes the cross-sectional configuration of the beam to contract.