JP5251306B2 - Optical fiber manufacturing method and manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for manufacturing an optical fiber which can cut wastes of resin and expensive cooling gas at the termination of drawing work. <P>SOLUTION: This method for manufacturing an optical fiber comprises a drawing stage of manufacturing an optical fiber G2 of a portion to be a product by drawing an optical fiber preform G while heating it to be softened; a determination stage for determining the termination of drawing work of the optical fiber G2 of the effective portion A to be the product in the optical fiber preform G, based on whether the predetermined conditions are satisfied or not; a termination stage of drawing work after the determination stage for determining the termination of drawing work, where in the termination stage of drawing work, the optical fiber is cut at a predetermined step prior to stopping of the optical fiber G2 during a slow-down work to decelerate the take-up speed of the optical fiber G2. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to an optical fiber manufacturing method and manufacturing apparatus for manufacturing an optical fiber by drawing an optical fiber preform heated in a heating furnace.

  Generally, an optical fiber is an optical fiber preform manufactured from a material such as quartz, softened by heating from the lower end side, and a glass fiber having a reduced diameter by applying tension to the softened portion of the optical fiber preform, Furthermore, it manufactures by coat | covering resin to the outer periphery. The process of reducing the diameter of the optical fiber preform to form an optical fiber is called drawing. The drawn optical fiber is drawn downstream of the pass line by take-up means such as a capstan roller and wound around a bobbin or the like (for example, see Patent Document 1).

JP 63-117925 A

When the drawing of the optical fiber of the effective part, which is the product of the optical fiber preform, is finished, the drawing finishing operation is performed to stop each device of the drawing apparatus to finish the drawing while drawing the remaining portion of the optical fiber preform. Do. Whether or not the drawing of the effective portion of the optical fiber, which is the product of the optical fiber preform, has been completed, has been determined by the operator by looking at factors such as the remaining preform length. After that, in the drawing finishing operation, the operator keeps the glass outer diameter within a certain range so that the drawn glass fiber and the optical fiber in which the resin is not cured do not come into contact with each peripheral device or component. In this manner, the take-up speed by the take-up means is gradually lowered while monitoring, and the optical fiber is cut when the take-up speed finally becomes zero.
By the way, in such wire drawing completion work, glass fiber that is not a product is coated with resin when the take-off speed is reduced from the start to the end of the work, and expensive helium gas for cooling is used. Therefore, these resins and helium gas are wasted.

  An object of the present invention is to provide an optical fiber manufacturing method and manufacturing apparatus capable of suppressing waste of resin and expensive cooling gas at the end of a drawing operation.

An optical fiber manufacturing method according to the present invention capable of solving the above-described problems is a drawing process for manufacturing a part of an optical fiber to be a product by drawing while heating and softening an optical fiber preform,
A drawing end determination step for determining whether or not the drawing of the optical fiber of the effective part as the product in the optical fiber preform satisfies a predetermined condition;
After the drawing end determination step, a drawing end operation step of performing a drawing end operation for ending the drawing, and an optical fiber manufacturing method comprising:
One of the predetermined conditions is that the fluctuation pattern of the drawing speed of the optical fiber matches a predetermined pattern,
During the drawing end work step, the optical fiber is cut at a predetermined stage before the stop of the optical fiber during the deceleration work for reducing the take-up speed of the optical fiber.

Further, the optical fiber manufacturing method according to the present invention includes a drawing step of manufacturing an optical fiber of a part to be a product by drawing while heating and softening the optical fiber preform,
A drawing end determination step for determining whether or not the drawing of the optical fiber of the effective part as the product in the optical fiber preform satisfies a predetermined condition;
After the drawing end determination step, a drawing end operation step of performing a drawing end operation for ending the drawing, and an optical fiber manufacturing method comprising:
When the predetermined condition is reached, the drawing end work is started on the condition that the heating temperature of the heating furnace for drawing the optical fiber preform is heated ,
During the drawing end work step, the optical fiber is cut at a predetermined stage before the stop of the optical fiber during the deceleration work for reducing the take-up speed of the optical fiber.

  In the optical fiber manufacturing method of the present invention, it is preferable that the drawing operation is automatically started based on the predetermined condition, and the optical fiber is automatically cut.

  Moreover, in the optical fiber manufacturing method of the present invention, it is preferable that the heating temperature of the optical fiber preform is started to be lowered after the drawing operation is started and before the optical fiber is cut.

An optical fiber manufacturing apparatus according to the present invention capable of solving the above problems is an optical fiber manufacturing apparatus for manufacturing an optical fiber by drawing while heating and softening an optical fiber preform,
A heating furnace for heating the optical fiber preform;
Feeding means for sending the optical fiber preform to the heating furnace;
Cooling means for cooling the glass fiber drawn from the optical fiber preform;
Coating means for coating the glass fiber cooled by the cooling means with resin;
A take-off means for taking an optical fiber in which the glass fiber is coated with a resin;
Cutting means for cutting the optical fiber;
Determining whether or not the drawing of the optical fiber of the effective part, which is the product in the optical fiber preform, has satisfied a predetermined condition, starting the drawing finishing operation to finish drawing, and reducing the drawing speed of the optical fiber Control means for cutting the optical fiber at a predetermined stage before stopping the optical fiber during work ,
One of the predetermined conditions is that the fluctuation pattern of the drawing speed of the optical fiber matches a predetermined pattern .

Further, the optical fiber manufacturing apparatus according to the present invention is an optical fiber manufacturing apparatus for manufacturing an optical fiber by drawing an optical fiber while heating and softening an optical fiber preform,
A heating furnace for heating the optical fiber preform;
Feeding means for sending the optical fiber preform to the heating furnace;
Cooling means for cooling the glass fiber drawn from the optical fiber preform;
Coating means for coating the glass fiber cooled by the cooling means with resin;
A take-off means for taking an optical fiber in which the glass fiber is coated with a resin;
Cutting means for cutting the optical fiber;
Determining whether or not the drawing of the optical fiber of the effective part, which is the product in the optical fiber preform, has satisfied a predetermined condition, starting the drawing finishing operation to finish drawing, and reducing the drawing speed of the optical fiber Control means for cutting the optical fiber at a predetermined stage before stopping the optical fiber during work,
The controller is characterized in that, when the predetermined condition is reached, the drawing end operation is started on the condition of a change in a heating temperature of a heating furnace for heating and drawing the optical fiber preform .

  Moreover, in the optical fiber manufacturing apparatus of the present invention, it is preferable that the control means starts to lower the heating temperature of the optical fiber preform after starting the drawing operation and before starting the cutting of the optical fiber.

  According to the manufacturing method and the manufacturing apparatus of the optical fiber of the present invention, the drawing finishing operation is started based on the condition during drawing, and the drawing is completed by cutting the optical fiber before the drawing of the optical fiber is finished. The amount of the resin and helium gas used for the glass fiber that is not a product after the drawing of the optical fiber is reduced as much as possible.

Hereinafter, an example of an embodiment of an optical fiber manufacturing method and a manufacturing apparatus according to the present invention will be described.
FIG. 1 is a schematic configuration diagram of a manufacturing apparatus capable of performing the optical fiber manufacturing method of the present embodiment.
As shown in FIG. 1, an optical fiber manufacturing apparatus 1 includes a vertical heating furnace 2 that heats an optical fiber preform G, a cooling device 6 that cools the drawn glass fiber G1, and a glass fiber G1. A die 8 for coating a resin around the periphery, a tension meter 17 for measuring the tension of the coated optical fiber G2, a capstan (take-out means) 13 for taking up the coated optical fiber G2, and dancer rollers 19 and 20 And winding bobbins 21 and 22 for winding the optical fiber G2.

The optical fiber manufacturing apparatus 1 includes a heating furnace 2 for heating the optical fiber preform G on the most upstream side. The heating furnace 2 includes a cylindrical furnace core tube 4 to which an optical fiber preform G is supplied, and a heating element 3 that is a heater surrounding the furnace core pipe 4. 4 rises in temperature, and a heating region is formed in the space inside. A heating area | region here is an area | region which becomes the temperature which can be drawn by softening glass, for example, is an area | region which is 1800 degreeC or more.
The heating furnace 2 is provided with a gas supply unit 21 that can supply a purge gas such as helium or nitrogen to the heating region.

  The upper part of the optical fiber preform G is held by the feeding means 5 and fed into the heating furnace 2 so that the lower end portion is positioned in the heating region inside the furnace core tube 4. Thus, the lower end side of the optical fiber preform G supplied into the heating furnace 2 is heated and softened in the heating region, and is drawn downward to reduce the diameter, thereby forming a glass fiber G1.

A cooling device (cooling means) 6 is provided below (downstream side) the heating furnace 2, and the glass fiber G <b> 1 immediately after leaving the heating furnace 2 is cooled by the cooling device 6.
The main body of the cooling device 6 is configured to be opened and closed by being divided into two in a direction away from the pass line of the glass fiber G1, and is usually used in a state of being joined and integrated with each other at the time of drawing. The cooling device 6 is formed with an insertion hole through which the glass fiber G1 is passed in the longitudinal direction at a central position where two members constituting the main body are closed. Cooling gas is fed into the insertion hole, and the glass fiber G1 inserted through the insertion hole is cooled. The main body of the cooling device 6 has a cooling flow path formed along the longitudinal direction in the main body, and a cooling fluid circulates in the inside. The cooling gas in the insertion hole is cooled by this cooling fluid, and the glass fiber G1 passes through the cooling gas atmosphere, so that the drawn glass fiber G1 is rapidly cooled from several hundred degrees C to near room temperature. Thereby, the shape of the glass fiber G1 is stabilized.
Note that helium gas having high thermal conductivity is used as the cooling gas. Since helium has a high thermal conductivity, it is suitable for use as a purge gas in the heating furnace 2 or a cooling solvent for the cooling device 6, but the cost is higher than that of nitrogen.

An upper shutter that can open and close the entrance of the insertion hole is provided at the upper end of the cooling device 6. Further, a lower shutter capable of opening and closing the outlet of the insertion hole is provided at the lower end of the cooling device 6. These upper shutter and lower shutter are closed during drawing to increase the cooling efficiency of the cooling device 6. The upper shutter and the lower shutter are closed so that a small-diameter hole is formed at the center thereof. The small-diameter hole has a slightly larger diameter than the drawn glass fiber G1. The glass fiber G1 passes through the small-diameter hole while maintaining a slight clearance between the upper shutter and the lower shutter.
A plurality of cooling devices 6 may be provided on the pass line.

  On the downstream side of the cooling device 6, for example, a laser beam type outer diameter measuring device 7 is provided, and the outer diameter of the glass fiber G 1 exiting the cooling device 6 is measured by the outer diameter measuring device 7. . In addition, it is preferable to measure the outer diameter here in each of the orthogonal axis directions on the plane in the direction orthogonal to the axis of the glass fiber G. The outer diameter measuring device 7 may be provided at a plurality of locations on the pass line.

  Below the outer diameter measuring instrument 7, as a coating means, a die 8 for applying an ultraviolet curable resin to the glass fiber G1 and an ultraviolet irradiation device 10 for curing the applied ultraviolet curable resin are provided. . The ultraviolet irradiation device 10 irradiates the optical fiber G2 coated with resin with, for example, a multi-lamp UV lamp to cure the ultraviolet curable resin. The glass fiber G1 is an optical fiber in which an ultraviolet curable resin is applied to the outer periphery by a die 8 and then the ultraviolet curable resin is cured and reacted by the ultraviolet irradiation device 10 to form a coating layer of the ultraviolet curable resin. G2.

Note that a tray 9 is provided on the downstream side of the die 8 and is usually disposed at a location off the pass line. The tray 9 enters the lower side of the die 8 when disconnected, and can receive the ultraviolet curable resin when the ultraviolet curable resin overflows from the die 8.
Further, a cutter (cutting means) 12 is provided between the die 8 and the tray 9 so that the optical fiber G2 drawn and coated with resin can be cut by the cutter 12. It has become.

  The optical fiber G2 on which the coating layer is formed is drawn into a capstan (take-out means) 13 through the guide roller 11. A predetermined tension is applied to the optical fiber G2 by a capstan 13. The capstan 13 includes a capstan belt 15 wound around a plurality of rollers 14, and a capstan roller 16 to which the capstan belt 15 is in close contact, and the capstan belt 15 and the capstan roller 16. However, the optical fiber G2 is held and pulled in. The capstan 13 pulls the optical fiber G2 further downstream.

  A tension meter 17 for measuring the tension of the optical fiber G2 is provided between the guide roller 11 and the capstan 13. The rotational speed of the capstan 13 is controlled so that the measured value of the outer diameter measuring device 7 becomes a predetermined value.

Further, on the downstream side of the capstan 13, a screening device 18 for performing a strength test such as pulling or bending of the optical fiber G2 is provided. Here, a predetermined tension is applied to the optical fiber G2 to test whether or not a certain strength condition is satisfied.
The optical fiber G <b> 2 that has undergone the strength test by the screening device 17 is sent to the take-up bobbins 21 and 22 via the dancer rollers 19 and 20. One of the take-up bobbins 21 and 22 is wound with an optical fiber G2 as a product, and the other take-up bobbin 22 has, for example, light drawn at the time of drawing failure or drawing completion work. The fiber G2 is wound up.

  The optical fiber manufacturing apparatus 1 having the above structure is provided with a control unit (control means) 23. The control unit 23 includes a feeding unit 5, a gas supply unit 21, a heating element 3, a cooling device 6, a die 8, a cutter 12, a tray 9, an ultraviolet irradiation device 10, a capstan 13, dancer rollers 18 and 19, and a winding bobbin 21. , 22 are controlled. Moreover, this control part 23 is connected to the outer diameter measuring instrument 7, the tension meter 17, and the screening apparatus 18, and the detection signal from these apparatuses is transmitted.

Next, the operation control by the optical fiber manufacturing apparatus 1 will be described.
FIG. 2 is a graph showing the relationship between the drawing time and the drawing speed with respect to the longitudinal direction of the optical fiber preform G. A descending curve indicated by a broken line in the vicinity of the right end in the graph indicates a conventional linear velocity.
As shown in FIG. 2, when the optical fiber preform G is drawn by the optical fiber manufacturing apparatus 1, the drawing speed when drawing the ineffective portion at the drawing start end (lower end) of the optical fiber preform G at the start of drawing. Increase gradually. Then, the drawing speed is increased to a predetermined value before the drawing of the effective part A, which is the effective part having the core part C, and becomes the product. When the effective part A is drawn, the glass fiber G1 is constant. The wire is drawn at a stable speed so as to have an outer diameter.

When the drawing of the effective part A having the core part C is finished, the non-effective part B that is not a product is subsequently drawn, so that the drawing of the effective part A is finished at the end of drawing (indicated by t in FIG. 2). It is effective to start work.
Here, in the optical fiber manufacturing apparatus 1 according to the present embodiment, the control unit 23 determines the timing to shift to the drawing end work based on the following conditions (1) to (3).

(1) Remaining length of optical fiber preform G The control unit 23 determines that the remaining length (Lo-L) of the optical fiber preform G is equal to or less than the set preform remaining length Ls based on the feed amount of the optical fiber preform G into the heating furnace. It is determined whether or not (Lo−L ≦ Ls). Here, the set base material remaining length Ls is a base material length set in advance as an ineffective part B of the optical fiber base material G that does not become a product even after the effective part A is drawn and then drawn, Lo is The base material length at the start, L, is the base material length used for drawing.

(2) Winding Length of Optical Fiber G2 The control unit 23 determines whether or not the total take-up length S of the optical fiber G2 taken by the capstan 13 is equal to or greater than the set total take-up length Ss (S ≧ Ss). The set total take-off length Ss is the length of the optical fiber obtained from the glass volume from the start of drawing of the optical fiber preform G to the end of drawing of the effective portion A and the cross-sectional area of the glass fiber G1.

(3) Fluctuation pattern of drawing speed of optical fiber G2 When a refractive index adjusting additive such as germanium is added to silica glass, the viscosity is lower than that of pure silica glass. Therefore, the non-effective part B is slightly hard with respect to the effective part A having the core part C to which the refractive index adjusting additive is added, so that there is no non-core part from the effective part A having the core part C. When the portion to be drawn to the effective part B is switched, the linear velocity varies. That is, during drawing of the effective part A, the drawing tension and the drawing speed are maintained almost constant, and the tension increases and the drawing speed decreases immediately after switching to the non-effective part B having a high viscosity. Increases the linear velocity as a reaction. This is a characteristic variation pattern when the effective part A is switched to the non-effective part B.
The control unit 23 detects the drawing speed from the take-up speed of the optical fiber G2 by the capstan 13, and this fluctuation pattern of the detection speed is a characteristic that occurs when the optical fiber preform G is switched from the effective part A to the non-effective part B. It is determined whether or not the linear velocity fluctuation pattern matches.

  The control unit 23 automatically determines a time point when all the conditions (1) to (3) are met and a predetermined time of about 1 minute has passed, as a timing for shifting to the drawing end work. And the control part 23 starts the completion | finish work of drawing automatically at this timing.

  In this drawing finishing operation, first, the non-defective product take-up bobbin 21 that takes up the product optical fiber G2 is switched to the defective product take-up bobbin 22 that takes up the non-product optical fiber G2.

Further, the control unit 23 controls the capstan 13 to reduce the resin supply pressure by a resin supply device (not shown) that supplies the resin to the die 8 while decreasing the linear velocity, and covers the glass fiber G1. Reduce the amount gradually.
Further, the gas supply unit 21 is controlled to switch the purge gas fed into the heating furnace 2 from a relatively expensive helium gas to a relatively inexpensive nitrogen gas, and the heating element 3 in the heating furnace 2 is controlled to control the heating furnace 2. Start to cool down inside.

  When the supply pressure of the resin to be supplied to the die 8 is sufficiently lowered to prevent the resin from overflowing from the die 8, the control unit 23 moves the cutter 12, and passes the optical fiber G2 being taken by running along the pass line. When the speed reaches a predetermined level (speed), cutting is performed on the downstream side of the die 8 (indicated by reference numeral t1 in FIG. 2). Thereby, the drawing of the glass fiber G1 from the ineffective portion B of the optical fiber preform G is forcibly terminated.

After cutting the optical fiber G2, the control unit 23 immediately controls the feeding means 5 to raise the optical fiber preform G to a predetermined height, and dice part of the glass fiber G drawn from the optical fiber preform G. Remove from 8.
Further, the tray 9 is moved and disposed below the dice 8, and the supply of resin to the dice 8 by the resin supply device is stopped.

Thereafter, the supply of the cooling gas to the cooling device 6 is stopped, and the upper shutter, the lower shutter, and the main body of the cooling device 6 are opened. Further, the UV lamp of the ultraviolet irradiation device 10 is turned off.
When the optical fiber G2 on the pass line is completely wound on the winding bobbin 22, the capstan 13 and the winding bobbin 22 are stopped, and the end operation is completed.
If a new optical fiber preform G is installed in place of the remaining optical fiber preform G for the next drawing operation, the temperature lowering in the heating furnace 2 is stopped and the temperature rise is started.

  As described above, according to the embodiment, the optical fiber G2 is cut and drawn based on the remaining length of the optical fiber preform G, the total take-up length of the optical fiber G2, and the drawing speed variation of the optical fiber G2. By determining the timing of the drawing end work to be finished and starting the drawing drawing work at this timing, the drawing drawing work can be shortened as much as possible. Then, the glass fiber G1 is drawn from the ineffective portion B of the optical fiber preform G, and the optical fiber G2 is cut while the optical fiber G2 is taken by the capstan 13, so that the glass fiber G1 that is not a product is obtained. On the other hand, the amount of helium gas used in the cooling device 6 and the amount of ultraviolet curable resin used in the die 8 can be minimized.

  That is, use the helium gas and the ultraviolet curable resin used from the end of drawing (indicated by reference numeral t1 in FIG. 2) (when the optical fiber is cut) to the end of conventional drawing shown by reference t2 in FIG. It will be finished.

  Further, since the drawing end work is performed without depending on the worker's manpower, the end work can be started accurately and the burden on the worker can be greatly reduced.

  In the above embodiment, an example is shown in which the timing for shifting to the end work is determined based on all the conditions of the remaining length of the optical fiber preform G, the take-up length of the optical fiber G2, and the fluctuations in the drawing speed of the optical fiber G2. However, the transition timing to the end work may be taken according to any two or more conditions.

Moreover, you may use together the temperature change of the heating furnace 2 as other conditions. When the shoulder portion (near the end portion) of the optical fiber preform G is heated, the optical fiber preform G is easily softened by the radiant heat, and the tension at the time of drawing decreases. For this reason, in the heating furnace 2, in order to prevent this softening, the temperature of the heating furnace 2 may be controlled to be gradually lowered during drawing.
That is, the control unit 23 uses this temperature change, for example, whether or not the difference between the drawing start temperature Ts and the current temperature Tc is 10 ° C. or more (Ts−Tc ≧ 10 ° C.). It may be used as a condition.

  Moreover, it is preferable that the cutting operation of the glass fiber G1 by the cutter 12 is automatically performed by the control unit 23 as in the above-described embodiment. However, the operator may cut the glass fiber G1 at the timing.

It is a schematic block diagram which shows an example of the manufacturing apparatus which can perform the manufacturing method of the optical fiber which concerns on this invention. It is a graph which shows the relationship between the drawing time with respect to the longitudinal direction of an optical fiber preform | base_material, and drawing speed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber manufacturing apparatus 2 Heating furnace 5 Feeding means 11 Cutter (cutting means)
13 Capstan (collection means)
23 Control unit (control means)
A Effective part (effective part)
G Optical fiber preform G1 Glass fiber G2 Optical fiber

Claims (7)

A drawing process for producing an optical fiber of a part to be a product by drawing while softening the optical fiber preform;
A drawing end determination step of determining whether or not the drawing of the optical fiber of the effective part that is the product in the optical fiber preform satisfies a predetermined condition;
After the drawing end determination step, a drawing end operation step of performing a drawing end operation for ending the drawing, and an optical fiber manufacturing method comprising:
One of the predetermined conditions is that the fluctuation pattern of the drawing speed of the optical fiber matches a predetermined pattern,
A method of manufacturing an optical fiber, wherein the optical fiber is cut at a predetermined stage before stopping the optical fiber during the decelerating operation for decelerating the drawing speed of the optical fiber during the drawing finishing operation step. A drawing process for producing an optical fiber of a part to be a product by drawing while softening the optical fiber preform;
  A drawing end determination step for determining whether or not the drawing of the optical fiber of the effective part as the product in the optical fiber preform satisfies a predetermined condition;
  After the drawing end determination step, a drawing end operation step of performing a drawing end operation for ending the drawing, and an optical fiber manufacturing method comprising:
  When the predetermined condition is reached, the drawing end work is started on the condition that the heating temperature of the heating furnace for drawing the optical fiber preform is heated,
  A method of manufacturing an optical fiber, wherein the optical fiber is cut at a predetermined stage before stopping the optical fiber during the decelerating operation for decelerating the drawing speed of the optical fiber during the drawing finishing operation step. The optical fiber manufacturing method according to claim 1, wherein the drawing operation is automatically started based on the predetermined condition, and the optical fiber is automatically cut. The method of manufacturing an optical fiber according to any one of claims 1 to 3, wherein the heating temperature of the optical fiber preform is started after starting the drawing operation and before starting the cutting of the optical fiber. . An optical fiber manufacturing apparatus for manufacturing an optical fiber by drawing an optical fiber preform while heating and softening the optical fiber preform,
A heating furnace for heating the optical fiber preform;
Feeding means for sending the optical fiber preform to the heating furnace;
Cooling means for cooling the glass fiber drawn from the optical fiber preform;
Coating means for coating the glass fiber cooled by the cooling means with resin;
A take-off means for taking an optical fiber in which the glass fiber is coated with a resin;
Cutting means for cutting the optical fiber;
Determining whether or not the drawing of the optical fiber of the effective part, which is the product in the optical fiber preform, has satisfied a predetermined condition, starting the drawing finishing operation to finish drawing, and reducing the drawing speed of the optical fiber Control means for cutting the optical fiber at a predetermined stage before stopping the optical fiber during work,
One of the predetermined conditions is that the fluctuation pattern of the drawing speed of the optical fiber matches a predetermined pattern. An optical fiber manufacturing apparatus for manufacturing an optical fiber by drawing an optical fiber preform while heating and softening the optical fiber preform,
A heating furnace for heating the optical fiber preform;
Feeding means for sending the optical fiber preform to the heating furnace;
Cooling means for cooling the glass fiber drawn from the optical fiber preform;
Coating means for coating the glass fiber cooled by the cooling means with resin;
A take-off means for taking an optical fiber in which the glass fiber is coated with a resin;
Cutting means for cutting the optical fiber;
Determining whether or not the drawing of the optical fiber of the effective part, which is the product in the optical fiber preform, has satisfied a predetermined condition, starting the drawing finishing operation to finish drawing, and reducing the drawing speed of the optical fiber Control means for cutting the optical fiber at a predetermined stage before stopping the optical fiber during work ,
When the predetermined condition is reached, the control means starts the drawing end operation on the condition of a change in heating temperature of a heating furnace for heating and drawing the optical fiber preform. Manufacturing equipment. 7. The optical fiber manufacturing apparatus according to claim 5, wherein the control unit starts the temperature decrease of the heating temperature of the optical fiber preform after the start of the drawing end work and before the start of cutting of the optical fiber. .

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