Fujikura Limited

Kenji Okada

Koichi Harada

Shoichiro Matsuo

Naritoshi Yamada

Shunichirou Hirafune

Munehisa Fujimaki

Shingo Matsushita

Junichi Takahashi

An optical fiber manufacturing method includes: coating an outer periphery of a bare optical fiber with a resin before curing by a coating device; and curing the resin with a coating curing device. The following equations are satisfied: t&#xd7;sin &#x3b8;&#x3e;T&#xd7; tan &#x3b8; and &#x3b8;=tan(d/L), where Tis a tension in the upstream of the coating device, t is the shear force applied to the bare optical fiber by the resin, d is the design maximum value of a deviation amount of an entry position of the bare optical fiber into the resin in the coating device with respect to the center axis of the die hole of the coating device, and L is the contact length between the resin and the bare optical fiber in the coating device along the center axis.

Optical fiber manufacturing method and optical fiber manufacturing apparatus

A method of winding an optical fiber includes winding the optical fiber using a bobbin that includes: a body portion having two end portions; and a pair of flanges, respectively disposed at the end portions in an axial direction of the body portion. An inner surface of each of the flanges is inclined toward an outer side in the axial direction and toward a radial outer side. The method further includes guiding the optical fiber to the bobbin using a final pulley. The bobbin and the final pulley reciprocate relative to each other in the axial direction at a traverse speed V (mm/sec) such that 0.0050&#x2264;&#x3b8; (rad)&#x2264;0.1000, where &#x3b8; is a delay angle, &#x3b8;=arctan (V/L), and L (mm) is a distance from a winding position of the optical fiber at the bobbin to the final pulley in a radial direction.

Method of winding optical fiber, method of manufacturing bobbin-wound optical fiber, optical fiber winder, and method of manufacturing optical fiber strand

A method of manufacturing an optical fiber, in which a coating is provided on a bare optical fiber, includes winding the optical fiber around a bobbin such that a strain sensing coefficient Tis greater than 0 and less than or equal to 973, and a one-layer strain &#x3b5;is greater than or equal to 0.01.

Method of manufacturing optical fiber and optical fiber

A method of manufacturing an optical fiber, in which a coating is provided on a bare optical fiber, includes winding the optical fiber around a bobbin such that a strain relaxation coefficient Tis less than or equal to 292, and an one-layer strain &#x3b5;is greater than or equal to 0.01.

A method of manufacturing an optical fiber of the invention includes: preparing one or more direction changers; drawing the bare optical fiber from an optical fiber preform; providing a coated layer on a periphery of the bare optical fiber; obtaining an optical fiber by curing the coated layer; changing the direction of the bare optical fiber at the position between the bare-optical-fiber formation position and the coated-layer provision position; detecting the position of the bare optical fiber in at least one of the direction changers; and adjusting the introduction flow rate of the fluid into the direction changer based on positional information obtained by the detection.

Method of manufacturing optical fiber, optical fiber manufacturing apparatus, and control apparatus therefor

A method of manufacturing an optical fiber of the invention includes: preparing a direction changer; drawing a bare optical fiber from an optical fiber preform, thereby forming the bare optical fiber; providing a coated layer made of a resin on a periphery of the bare optical fiber; obtaining an optical fiber by curing the coated layer; changing a direction of the bare optical fiber by use of the direction changer; measuring a drawing velocity of the optical fiber; and adjusting a length of the bare optical fiber from a drawing unit to a coating unit by controlling a position of the direction changer based on a measurement value of the drawing velocity, the drawing unit forming the bare optical fiber, the coating unit providing the coated layer on the periphery of the bare optical fiber.

A control device which is used in a manufacturing apparatus of an optical fiber, the manufacturing apparatus including a drawing unit and a coating unit. The control device includes: one or a plurality of non-contact holding portions which hold the bare optical fiber at any position between the drawing unit and the coating unit; a position detection unit; and a control unit which controls a flow rate of a fluid introduced into the non-contact holding portion on the basis of the floating position detected by the position detection unit. The non-contact holding portion comprises a guide groove. The control unit detects the floating position of the bare optical fiber at at least one of the non-contact holding portions, compares the detected floating position with a predetermined reference floating position, and controls a flow rate of the fluid introduced into the non-contact holding portions.

Control device and manufacturing apparatus of optical fiber

A control device which is used in a manufacturing apparatus of an optical fiber, the manufacturing apparatus including: a drawing unit; a coating unit; and a curing unit which cures the coating layer. The control device includes: one or a plurality of direction changing devices which change a direction of the bare optical fiber at any position between the drawing unit and the coating unit; a position detection unit which detects a position of the bare optical fiber in the direction changing device; an outer diameter measurement unit which measures an outer diameter of the bare optical fiber; and a control unit which controls a flow rate of a fluid introduced into the direction changing device on the basis of the position of the bare optical fiber measured by the position detection unit and the outer diameter of the bare optical fiber measured by the outer diameter measurement unit.

Control device, and manufacturing apparatus of optical fiber

A bare optical fiber coating device includes: a nipple having a nipple hole through which a bare optical fiber is inserted vertically from above; an intermediate die that has an intermediate die hole through which the bare optical fiber passing through the nipple hole is inserted and that is disposed vertically below the nipple; a first coating die that has a first coating die hole through which the bare optical fiber passing through the intermediate die hole is inserted and that is provided vertically below the intermediate die; and a first resin circulation chamber that is formed by the nipple and the intermediate die, is formed between the nipple hole and the intermediate die hole in an annular shape surrounding the bare optical fiber passing through the nipple hole, and is configured to circulate liquid resin.

Bare optical fiber coating device and bare optical fiber coating method

An apparatus for manufacturing an optical fiber including: a drawing portion; a coating portion; and a curing portion, wherein: a direction changer which changes a direction of the bare optical fiber is disposed in any position from the drawing portion to the coating portion; the direction changer includes a guide groove which guides the bare optical fiber; a blowout port of a fluid which floats the bare optical fiber wired along the guide groove is formed along the guide groove in the guide groove; and in the blowout port, the Reynolds number in an inlet wire portion of the bare optical fiber to the guide groove and an outlet wire portion from the guide groove is greater than the Reynolds number in an intermediate portion between the inlet wire portion and the outlet wire portion.

Apparatus for manufacturing an optical fiber

An apparatus for manufacturing an optical fiber, including a drawing portion, a coating portion, and a curing portion; wherein a direction changer which changes a direction of the bare optical fiber is disposed in any position from the drawing portion to the coating portion, the direction changer includes a guide groove which guides the bare optical fiber, a blowout port of a fluid which floats the bare optical fiber wired along the guide groove is formed along the guide groove in the guide groove, and an average flow rate or a highest flow rate of the fluid in an inlet wire portion of the bare optical fiber to the guide groove, and an outlet wire portion from the guide groove is faster than a lowest flow rate of the fluid in an intermediate portion between the inlet wire portion and the outlet wire portion in the blowout port.

A method of manufacturing an optical fiber of the invention includes: preparing a direction changer; drawing the bare optical fiber from an optical fiber preform; providing a coated layer on a periphery of the bare optical fiber; obtaining an optical fiber by curing the coated layer; changing a direction of the bare optical fiber at a position between a bare-optical-fiber formation position and a coated-layer provision position; and measuring the outer diameter of the coated layer; and adjusting the length of the bare optical fiber from a drawing unit to a coating unit by controlling a position of the direction changer based on a measurement value of the outer diameter, the drawing unit forming the bare optical fiber, the coating unit providing the coated layer on the periphery of the bare optical fiber.

A manufacturing method of an optical fiber includes drawing an optical fiber preform and forming a bare optical fiber, coating an outer circumference of the bare optical fiber with a coating layer including a resin, curing the coating layer and forming an optical fiber by curing the coating layer, and changing a direction of the bare optical fiber using one or a plurality of direction changing devices at any position between a position where the bare optical fiber is formed and a position where the coating is performed. The direction changing device includes a guide groove which guides the bare optical fiber, and an internal space portion into which a fluid is introduced from an outside, and in the guide groove, an outlet through which the fluid in the internal space portion is blown to float the bare optical fiber in the guide groove is formed.

Manufacturing method, control device, and manufacturing apparatus of optical fiber

A manufacturing method of an optical fiber includes drawing an optical fiber preform and forming a bare optical fiber, coating an outer circumference of the bare optical fiber with a coating layer including a resin, and holding the bare optical fiber using one or a plurality of non-contact holding portions at any position between a position where the bare optical fiber is formed and a position where the coating is performed. The non-contact holding portion includes a guide groove which guides the bare optical fiber, and an internal space portion into which a fluid is introduced from an outside, in the guide groove, and an outlet through which the fluid in the internal space portion is blown to float the bare optical fiber in the guide groove is formed.

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Sakura, Japan

Kenji Okada