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. 07, 1996
Filed:
Jan. 28, 1994
Kenji Yamauchi, Tokyo, JP;
Masahiko Nakayama, Kanagawa, JP;
NEC Corporation, , JP;
Abstract
An airtight sealing method for a leading portion of an optical fiber, which provides high airtight sealing effect and is suitable for mass-production, is provided. The airtight seal structure of a leading portion of an optical fiber according to the present invention comprises an optical fiber and a metal pipe having a through-hole for receiving the optical fiber and adapted to connect an inner portion of the leading portion to an outer portion of the leading portion. A pair of glass pipes each having a through-hole receives the optical fiber and adapted to be inserted into the metal pipe. A low melting point glass material is disposed between the glass pipes in the metal pipe and seals the inner and outer portions of the leading portion by filling a space between an inside of the metal pipe and the optical fiber when heated. Particularly, the melting point of the glass pipes is higher than the melting point of the low melting point glass material so that they are sealed by the low melting point glass material and fixedly bonded to an inner wall of the metal pipe when the low melting point glass material becomes molten state by heating.