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. 09, 1977
Filed:
Sep. 17, 1975
Hideo Todokoro, Tokyo, JA;
Tsutomu Komoda, Tokyo, JA;
Hitachi, Ltd., , JA;
Abstract
A field emission electron gun provided in a housing defining a vacuum chamber comprises a field emission tip as an electron source, an anode spaced from and facing the field emission tip, the field emission tip and the anode defining a space in which the field emission tip produces electrons. An evaporation source disposed in the vacuum chamber, the evaporating material from which forms evaporation layers on the inner surface of the vacuum chamber and the anode surface. A first voltage source is interconnected between the field emission tip and the anode, in order to accelerate the electrons from the tip toward the anode, and a second voltage source is connected with the evaporation source to supply a current for the evaporation. The evaporation layers are formed before the first voltage source is actuated, whereby reactive gases adhering to and embedded to the inner surface of the vacuum chamber and the anode are suppressed from being drawn out by electron bombardment.