JPH0158136B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for resin coating optical fibers. More specifically, the present invention relates to a resin coating apparatus during the optical fiber manufacturing process in which a base material narrowed by a chuck is suspended in a spinning furnace and drawn from one end at a constant speed.

An example of a conventional coating device of this type is shown below.
As shown in the figure.

Rod 1, which is the base material of the optical fiber, is connected to a dummy rod (not shown), etc., and a chuck (not shown)
The tip is guided into the spinning furnace. The base material softened by the spinning furnace 2 is drawn at one end by a wire drawing device to form an optical fiber 3 having a predetermined diameter.
The outer diameter of the optical fiber 3 derived from the optical fiber 3 is measured by an outer diameter measuring device 4 in an optical or non-contact manner, and immediately after that, it is passed through a resin coating die 5 to protect the surface of the optical fiber 3. is coated with a resin and dried in a drying oven 6.

In the above configuration, it is necessary to center the outer diameter measuring device 4, that is, to slightly move the measuring device 4 in the horizontal direction and adjust its relative position so that the optical fiber is located in the center of the built-in position detection laser beam, for example. There is. In addition, it is necessary to apply a uniform resin coating to the optical fiber 3 so as not to cause uneven thickness, and therefore, a resin coating die 5 is used.
centering is also performed by slightly moving it in the horizontal direction.

Conventionally, in order to perform these centering operations, separate horizontal fine movement mechanisms 7 were used.
and 8. This results in the following drawbacks. That is, the position on the horizontal plane may change moment by moment during spinning of the optical fiber 3 due to bending of the rod 1 of the base material or misalignment of the connection part with the dummy rod connected to it, but the conventional structure In this case, since it is difficult to correct the position of the resin coating die 5 in accordance with the positional change of the optical fiber 5, an optical fiber with uneven thickness is likely to be produced. In addition, it is necessary to center the outer diameter measuring device 4 and the resin coating die 5 separately, which takes time and often causes disconnection of bare optical fibers.

Furthermore, the centering of the resin coating die 5 requires fine adjustment on the μm order, which requires skill.

The present invention was made based on the above circumstances, and
An optical fiber resin in which an optical fiber outer diameter measuring device and a resin coating die are integrally attached via a stand, making it possible to obtain an optical fiber with a resin coating without uneven thickness and facilitating centering work. The purpose is to provide a coating device.

An embodiment of the present invention will be described below based on the drawings.

In FIG. 2, an outer diameter measuring device 4 is fixed to a pedestal 10 on the upper surface of the frame 9, and a resin coating die 5 is fixed to a pedestal 11 on the lower surface. That is, the die 5 is attached to a die holder 12, and when the holder 12 is attached to the pedestal 11, it is accurately centered with the outer diameter measuring device 4 before being attached to the pedestal 9.

The above-mentioned outer diameter measuring device 5 is a commonly used optical method, etc., which is a non-contact method that vibrates a laser beam at a predetermined amplitude and irradiates the optical fiber, and measures the outer diameter of the optical fiber 3 from its shadow. Use a container.

A fine movement mechanism 13 is provided on the pedestal 9, and by rotating a handle 14, the outer frame (not shown) is moved.
A pedestal 9, which is slidably attached to the frame 9, moves slightly in the horizontal direction (X direction and Y direction) together with the outer diameter measuring device 4 and the resin coating die 5.
Note that this fine movement mechanism can also be driven by a motor (not shown) or the like.

Further, in the figure, the same parts as in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted.

With the above configuration, the position of the optical fiber 3 coming out of the spinning furnace 2 is detected by a position detection laser beam provided in the outer diameter measuring device 4 to detect whether or not the optical fiber is located at the center of the laser beam. always monitor,
If the fine movement mechanism is controlled in a feedback manner so as not to shift its center position, the resin coating die 5 is also always centered via the mount 9, so that uneven thickness can be prevented over the entire length of the optical fiber 3. It is possible to manufacture an optical fiber 3 having a concentric circular shape. The above-mentioned feedback control can be performed automatically when the optical fiber position fluctuates significantly, and can be performed manually when the fluctuation is small.

In addition, the centering work only needs to be done once, which shortens the work, and avoids applying shear stress to the optical fiber that would otherwise be applied to the centering work separately, thereby increasing the probability of optical fiber breakage. will also decrease.

Further, since the positioning of the resin coating die 5 is automatically performed by the outer diameter measuring device 4, no skill is required, and uniform resin coating work can be easily performed.

Next, FIG. 3 shows the state of uneven thickness when using a conventional resin coating device and a resin coating device of the present invention. That is, as shown in FIG. 1A, the center position of the optical fiber is a, the center position of the coating resin 15 is b, and the distance between a and b is the positional deviation distance t. If the vertical axis of the figure B is colored with the above-mentioned positional deviation distance t (μm), and the horizontal axis is colored with the optical fiber length (Km), it is clear from the figure that the optical fiber length increases in conventional example P. Accordingly, the positional deviation distance t increases, but in the example Q of the present invention, the positional deviation hardly occurs and is substantially uniform regardless of the optical fiber length.

In the embodiments of the present invention, an example of single coating has been described, but it goes without saying that the present invention can also be applied to so-called double coating in which primer coating and back coating are applied.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a conventional optical fiber resin coating device, FIG. 2 is a schematic diagram of an optical fiber resin coating device showing an embodiment of the present invention, and FIGS. 3A and 3B are a conventional device. FIG. 3 is a diagram and a graph showing the positional deviation of the resin coating on the optical fiber between the device and the device according to the present invention. 1... Rod, 2... Spinning furnace, 3... Optical fiber, 4... Outer diameter measuring device, 5... Resin coating die, 6... Drying oven, 9... Frame, 13...
Fine movement mechanism, 15...Coating resin.

Claims (1)

[Claims] 1. An outer diameter measuring device that measures the outer diameter of an optical fiber led out from a spinning furnace in a non-contact state, a resin coating die that applies a coating of a predetermined thickness after passing through this measuring device, and these outer diameter measuring instruments and 1. A resin coating device for optical fibers, comprising a pedestal to which a resin coating die is integrally attached, and a fine movement mechanism to slightly move and center the pedestal in the horizontal direction.