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:
May. 08, 2012
Filed:
Oct. 17, 2008
Applicants:
Masanori Fukui, Akita, JP;
Koichi Suzuki, Akita, JP;
Takeshi Fujita, Akita, JP;
Inventors:
Assignees:
Japan Super Quartz Corporation, Akita-Ken, JP;
Sumco Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C30B 11/00 (2006.01); C30B 15/00 (2006.01); C30B 21/06 (2006.01); C30B 27/02 (2006.01); C30B 28/10 (2006.01); C30B 30/04 (2006.01); C30B 17/00 (2006.01); C30B 21/02 (2006.01); C30B 28/06 (2006.01); C30B 35/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
The arc discharge apparatus comprises a plurality of carbon electrodes connected to respective phases of a power supply for heating a silica powder and causing it to fuse by generating arc discharge between the carbon electrodes. All of the carbon electrodes have a density in a range from 1.30 g/cmto 1.80 g/cm, and variability in density among the carbon electrodes is 0.2 g/cmor less. The carbon particles that constitute the carbon electrodes preferably have a particle diameter of 0.3 mm or less.