PURPOSE: To obtain a flexible image guide, by using a triple optical fiber for forming a clad layer and an acid soluble glass layer on the outside circumference of a core glass fiber, forming it like a hexagonal pole, heating and elongating it, and thereafter, removing an acid soluble material.
CONSTITUTION: A triple optical fiber 1 is formed by heating and elongating core glass 2, clad glass 3 and acid soluble glass 73, by a triple crucible method. This fiber 1 is stuck to a band-like optical fiber 23 by an organic adhesive material, and by using it, a hexagonal pole-like optical fiber 22 is formed. Subsequently, this hexagonal pole-like fiber 22 whose adjacent sides make 120° to each other is heated and is elongated so as to be reduced to a shape of about 1/15. Also, both ends of this hexagonal pole-like fiber 22 are hardened by heat resistance resin 20, and thereafter, it is soaked into an acid treatment liquid, and acid soluble glass 4, 22a is removed. In this way, it is possible to obtain an image guide of a gastroscope, whose both ends are fixed like a hexagonal pole, and whose intermediate part has flexibility.
MARUYAMA TSUTOMU
KUMAKURA NORIYUKI
KUWAYAMA SHIGEO
| JPS5674205A | 1981-06-19 | |||
| JP45037740A | ||||
| JPS5734505A | 1982-02-24 |