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. 26, 1999
Filed:
Feb. 24, 1998
Akira Fujinoki, Fukushima, JP;
Akihiko Sugama, Fukushima, JP;
Masaatsu Kataoka, Fukui, JP;
Wolfgang Englisch, Kelkheim, DE;
Shin-Etsu Quartz Products Co., Ltd., Tokyo, JP;
Haraeus Quarzglas GmbH, Hanau, DE;
Abstract
A method of preparing a ball-shaped synthetic silica glass optical article. The method includes a step of providing a rod-shaped synthetic silica glass having end faces at both sides thereof and having fewer cords per unit volume viewed in a direction perpendicular to a line connecting the end faces relative to the number of cords per unit volume viewed in a direction along the line connecting the end faces. The synthetic silica glass being optically homogeneous in the direction perpendicular to the line connecting the end faces. The method includes the further step of establishing support portions at the end faces of the synthetic silica glass. The rod-shaped synthetic silica glass is thereupon heated while being rotated around an axis connecting the support portions wherein a molten zone is formed. The molten zone of the rod-shaped synthetic silica glass is thereupon deformed by the application of pressure along the axis connecting the support portions whereupon a high purity ball-shaped optical article, having end faces and a side face positioned between the end faces, is formed. The optical article is characterized by a lesser number of cords per unit volume, viewed in a direction perpendicular to a line connecting the end faces relative to the number of cords per unit volume viewed in a direction along the line connecting the end faces. The rod-shaped synthetic silica glass is furthermore optically homogeneous in a direction perpendicular to the line connecting the end faces. The method is concluded by cutting the ball-shaped optical article at the edge support portions.