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

Patent metadata

Field	Value
Publication number	US-2016347646-A1
Application number	US-201615147180-A
Country	US
Kind code	A1
Filing date	May 5, 2016
Priority date	May 27, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

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.

First claim

What is claimed is:

1 . A manufacturing method of an optical fiber, the method comprising:
drawing an optical fiber preform and forming a bare optical fiber; coating an outer circumference of the bare optical fiber with a coating layer comprising 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, wherein: the direction changing device comprises 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, 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; and a position of the bare optical fiber at at least one of the direction changing devices is detected, an outer diameter of the bare optical fiber is measured, and a flow rate of the fluid introduced into the direction changing devices is controlled on the basis of the position and the outer diameter of the bare optical fiber.

2 . The manufacturing method of an optical fiber according to claim 1 , further comprising:
determining a target floating position in the direction changing device on the basis of a measurement value of the outer diameter of the bare optical fiber; comparing the target floating position and a result of detection of the position of the bare optical fiber are compared to each other; and controlling the flow rate of the fluid introduced into the direction changing device is controlled so as to reduce the difference therebetween.

3 . The manufacturing method of an optical fiber according to claim 2 ,
wherein the flow rate of the fluid introduced to all the direction changing devices among the plurality of direction changing devices is controlled so as to reduce the difference between the result of the detection of the position of the bare optical fiber at at least one direction changing device among the plurality of direction changing devices and the target floating position.

4 . The manufacturing method of an optical fiber according to claim 2 ,
wherein the target floating position is determined on the basis of a relative deviation of an optimal floating position of the bare optical fiber obtained in Expression (1):

Δ



r

=

D
-

D
0

2
×
tan



θ

(
1
)

where Δr is the relative deviation [mm] of the optimal floating position from an optimal floating position of a reference bare optical fiber,
θ is an inclination angle [°] of an inner side surface of the guide groove,
D is the outer diameter [mm] of the bare optical fiber, and
D 0 is an outer diameter [mm] of the reference bare optical fiber.

5 . The manufacturing method of an optical fiber according to claim 2 ,
wherein, before a drawing velocity of the optical fiber reaches a steady level, the target floating position is determined on the basis of a relative deviation of an optimal floating position of the bare optical fiber obtained in Expression (2):

Δ



r

=

D
-

D
0

2
×
tan



θ

+
α

(
2
)

where Δr is the relative deviation [mm] of the optimal floating position from an optimal floating position of a reference bare optical fiber,
θ is an inclination angle [°] of an inner side surface of the guide groove,
D is the outer diameter [mm] of the bare optical fiber,
D 0 is an outer diameter [mm] of the reference bare optical fiber, and
α is an offset amount [mm].

6 . A control device which is used in a manufacturing apparatus of an optical fiber,
the manufacturing apparatus comprising:
a drawing unit which draws an optical fiber preform and forms a bare optical fiber;
a coating unit which coats an outer circumference of the bare optical fiber with a coating layer comprising a resin; and
a curing unit which cures the coating layer, and
the control device comprising:
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,
wherein the direction changing device comprises a guide groove which guides the bare optical fiber and an internal space portion into which the fluid is introduced from the outside, wherein 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, and wherein the control unit detects the position of the bare optical fiber at at least one of the direction changing devices, measures the outer diameter of the bare optical fiber, and controls a flow rate of the fluid introduced into the direction changing devices on the basis of the position and the outer diameter of the bare optical fiber.

Assignees

• Fujikura Ltd

Inventors

• Okada Kenji

Classifications

• C03C25/106

  Single coatings · CPC title

• Y02P40/57

  Improving the yield, e-g- reduction of reject rates · CPC title

• G02B6/02395

  Glass optical fibre with a protective coating, e.g. two layer polymer coating deposited directly on a silica cladding surface during fibre manufacture (G02B6/02052, G02B6/02057, G02B6/024, G02B6/032, G02B6/105, G02B6/14 take precedence; coating on fibre gratings G02B6/02104; multilayer core or cladding G02B6/036; reinforcing splice joints G02B6/2558; optical cables, i.e. comprising protective structures external to the protective coating such as a jacket or plural coated optical fibres G02B6/44; coating of glass to obtain optical fibres C03C25/104) · CPC title

• C03B37/032 Primary

  for glass optical fibres · CPC title

• C03B37/0253

  Controlling or regulating (for glass fibre manufacture in general C03B37/07) · CPC title