JPS5742006A - Production of optical fiber bundle for image transmission - Google Patents

Abstract

PURPOSE:To make the titled optical fiber bundle adaptable to heat resistant fiber scopes for high heat devices and the like by putting glass tubes or required length on both end parts bundled with plural pieces of optical fibers, and uniformly heating the outside circumferential walls of the tubes thereby melt-sticking the glass in one body to the optical fibers. CONSTITUTION:Striplike aggregate bundles 2, which are paralleled with optical fibers (particularly of silica system) 1, are tentatively secured and are cut, are put into a forming jig with both end parts being superposed, and further the respective bundles 2 are tentatively adhered and their end parts 3 are inserted into quartz glass tubes 4 of required length. The outside circumferences of the tubes 4 are then uniformly heated to soften and shrink with an oxyhydrogen burner or the like whereby they are melt-stuck to the outside circumferences of the end parts. This yields the end parts 3' which are formed in one body without deviation in the arrangement of the fibers 1. Both end faces are then precisely polished to make optical image transmission and reception surfaces, whereby the fire-resistant optical fiber bundle 5 having the heat resistant and mechanically tough receiving end faces for observation of the inside of blast furnaces and the like is obtained.