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

Patent metadata

Field	Value
Publication number	US-9878935-B2
Application number	US-201615147180-A
Country	US
Kind code	B2
Filing date	May 5, 2016
Priority date	May 27, 2015
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

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;
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;
determining a target floating position in the one or a plurality of direction changing devices on the basis of a measurement value of an outer diameter of the bare optical fiber;
comparing the target floating position and a result of detections of a position of the bare optical fiber to each other; and
controlling a flow rate of a fluid introduced into the one or a plurality of direction changing devices so as to reduce a difference therebetween,
wherein:
the one or a plurality of direction changing devices comprise a guide groove which guides the bare optical fiber, and an internal space portion into which the 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;
a position of the bare optical fiber at at least one of the one or a plurality of 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; and
the target floating position is based on
setting an inclination angle θ [°] of an inner side surface of the guide groove,
detecting the outer diameter D [mm] of the bare optical fiber,
setting the outer diameter D 0 [mm] of a reference bare optical fiber,
calculating a relative, deviation Δr [mm], which represents a relative deviation of the optimal floating position from a reference position, of an optimal floating position of the bare optical fiber obtained in Expression (1):

Δ
⁢

⁢
r

=

D
-

D
0

2
×
tan
⁢

⁢
θ

,
and

(
1
)

determining the target floating position as a position deviated from the reference position toward the outside in a radial direction by Δr.

2. The manufacturing method of an optical fiber according to claim 1 ,
wherein the flow rate of the fluid introduced to all the direction changing devices among the one or a 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 one or a plurality of direction changing devices and the target floating position.

3. 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;
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;
determining a target floating position in the one or a plurality of direction changing devices on the basis of a measurement value of an 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 to each other; and
controlling a flow rate of a fluid introduced into the one or a plurality of direction changing devices so as to reduce a difference therebetween, wherein:
the one or a plurality of direction changing devices comprise a guide groove which guides the bare optical fiber, and an internal space portion into which the 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;
a position of the bare optical fiber at at least one of the one or a plurality of 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 one or a plurality of direction changing devices is controlled on the basis of the position and the outer diameter of the bare optical fiber; and
the target floating position is based on
setting an inclination angle θ [°] of an inner side surface of the guide groove,
detecting the outer diameter D [mm] of the bare optical fiber,
setting the outer diameter D 0 [mm] of a reference bare optical fiber,
setting an offset amount α [mm]
calculating a relative deviation Δr [mm], which represents a relative deviation of the optimal floating position from a reference position, of an optimal floating position of the bare optical fiber obtained in Expression (2):

Δ
⁢

⁢
r

=

D
-

D
0

2
×
tan
⁢

⁢
θ

+
α

,
and

(
2
)

Assignees

• Fujikura Ltd

Inventors

• Okada Kenji

Classifications

• C03B37/0253

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

• C03C25/106

  Single coatings · CPC title

• C03B37/075

  Manufacture of {non-optical} fibres or filaments consisting of different sorts of glass or characterised by shape, e.g. undulated fibres (C03B37/022, C03B37/027, C03B37/028 take precedence; light guides G02B6/00) · 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