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:
Oct. 01, 1996
Filed:
Sep. 09, 1994
Hideo Sugai, Aichi-ken, JP;
Katsutaro Ichihara, Kanagawa-ken, JP;
Nobuaki Yasuda, Kanagawa-ken, JP;
Michiko Okubo, Kanagawa-ken, JP;
Kabushiki Kaisha Toshiba, Kanagawa-ken, JP;
Abstract
A plasma discharge apparatus includes a chamber in which plasma discharge is produced; an antenna composed of a loop coil formed from an electric conductor which can be supplied with R.F. power so as to produce a high frequency electric field in the chamber; and an electric shield of a shield layer of non-magnetic electrically conductive material which toroidally surrounds the coil and which has openings. The shield layer is grounded and electrically connected to the antenna so as to be a return circuit. The electric shield can be formed from a strip electric conductor toroidally wound to provide a spiral gap opening between turns. The strip can further be toroidally wound over the spiral gap but separated from the underlying strip layer to form a double layer shield.