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:
Jun. 07, 1994
Filed:
Nov. 30, 1992
Yasumitsu Wada, Tsurugashima, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
An electron beam projection apparatus including electron injection unit for irradiating an object with an electron beam. The electron injection unit includes a substrate, a cathode formed on the substrate for emitting the electrons, a control electrode formed on the substrate via an insulation layer in a manner enclosing the cathode for accelerating the electrons, and an anode formed on the control electrode via an insulation layer in a manner enclosing the cathode for converging the electron beam. The electron beam projection apparatus further including detecting unit formed on the anode via an insulation layer for detecting secondary electrons emitted from the object irradiated with the electron beam and differential pumping unit for producing a low vacuum condition in an space where the electron beam travels from the microscopic electron injection unit to the object. By maintaining a low vacuum condition, in the area where the electron beam is projected and detected, by using simple structural differential pumping unit, the detection accuracy can be achieved since the secondary electrons are amplified in the low vacuum area by the ionization of gas molecules.