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:
Mar. 12, 2002
Filed:
Jun. 21, 1999
Yoshitaka Ohshima, Shizuoka, JP;
Takeshi Fukuyo, Shizuoka, JP;
Nobuo Ohkawai, Shizuoka, JP;
Shinichi Irisawa, Shizuoka, JP;
Koito Manufacturing Co., Ltd., Tokyo, JP;
Abstract
The pinch-sealing for the first one of a pair of molybdenum foils is not performed by flowing inactive gas within a quartz glass tube like the prior art but performed in a manner that the lower end portion of the quartz glass tube is sealed, and then and a pinch seal estimation portion is squeezed by a pincher while air within the quartz glass tube is exhausted from the upper end portion thereof so that pressure within the quartz glass tube becomes in a negative pressure state of 100 torr or less and while heating the pinch seal estimation portion Accordingly, at the time of the squeezing, the inner wall surface of the pinch seal estimation portion thus heated is attracted to the molybdenum foil side thereby to form fine concave and convex portions on the interfaces between the molybdenum foil and the quartz glass tube so that the molybdenum foil and the quartz glass tube are placed in an engaged state and the contact area therebetween is increased.