JPS60108812A - Optical fiber cable - Google Patents

Abstract

PURPOSE:To prevent heating of an optical fiber which is caused when a laser light is transmitted, by a supporting constitution which stabilizes the optical fiber exit end of a narrow-diameter optical fiber cable and the position of a condenser lens. CONSTITUTION:A supporting member 13 has a diameter sufficiently larger than that of a fiber 1 projected from a pipe 12 and supports a projecting part 13a only near the front end of the fiber 1. The inside circumferential face is formed to a reflective face, and the outside circumferential face is engaged with a lens holder 15. A condenser lens 16 is inserted into the lens holder 15 and is fixed by engagement with the supporting member 13 while keeping the optical position for the exit end of the optical fiber 1 by a step part having a notch 15a and a lens retainer 17 consisting of a refractory member. As the result, the optical fiber 1 is regulated in the space of the narrow-diameter part 13a, and deformation due to bend or the like is prevented. Further, the center of the condenser lens 16 and the center of the optical fiber exist always the same axial line.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an optical fiber cable that guides a laser beam to all destinations in, for example, a laser scalpel device, a laser processing machine, etc.

Conventional configuration and its problems When all laser beams are incident on an optical fiber, most of the laser beams are emitted from the output end, but some of the laser beams are absorbed at the input/output end and inside the optical fiber, so the optical fiber generates heat. Longitudinal elongation occurs due to expansion. % of the heat generated by optical fibers is near the input and output ends.
Therefore, a conventional method has been used to prevent heat generation by setting the output end side of the optical fiber in a sound-free state and setting the protrusion amount to be long. Referring to FIG. 1, the optical fiber 1 is covered with a protective tube 3 made of plastic or metal, and is integrally fixed to the protective tube 3 via a retaining member 2 with a set screw 4. As shown in FIG. However, the tip of the optical fiber 1 is made to fully protrude a certain length from the protective tube 3 due to problems such as heat generation. 5 is a condensing lens.

It is fixed to the protective tube 3 by tightening the threaded portion 6a of the lens holder 6. A laser beam incident on the optical fiber 1 is focused from the output end by a condenser lens 6 and irradiated to the outside.

However, since the optical fiber 1 that is not assembled into the protective tube 3 has its tip protruding in a free state, it is not always in a straight state parallel to the protective tube 3.
It has bends due to internal and external factors before or after installation,
It may deviate from the parallel state. When the parallel state is deviated from the parallel state, as is clear in FIG. Not only will the transmission efficiency of the optical fiber cable decrease, but the irradiated part of the protective tube 3 will become hot, making it very dangerous if it comes into contact with hands or fingers during operation or with the human body when used inside the human body, such as an endoscope. There was a problem.

In addition, due to thermal expansion of the output end of the optical fiber 1 in a free state, the optical positional relationship with the condensing lens 5 changes, resulting in a decrease in power due to a decrease in transmission efficiency, and an inability to obtain the minimum focusing diameter. Problems such as a decrease in power density occur.

OBJECTS OF THE INVENTION In view of the above-mentioned problems, the present invention provides an optical fiber cable that completely prevents the heat generation of optical fibers generated when laser beams are transmitted through the optical fiber cable. In the configuration of the ends.

In particular, what is the location of the optical fiber output end and condensing lens in a small-diameter optical fiber cable? It has a support structure that stabilizes it.

Description of examples An embodiment of the present invention is shown in FIGS. 2, 3, and 4.

This will be explained based on FIG.

FIG. 2 is an overall view of a laser irradiation device 8 using an optical fiber cable according to the present invention. Laser irradiation device 8
Inside is a laser excavator (
(not shown) is incorporated.

The optical fiber cable is generally composed of a protective tube 9, a main body joint part 10, and a worn bead part 11. FIG. 3 is a side sectional view of the output part of the optical fiber cable, FIG. 4 is a perspective view of five people with the tip of FIG. 3 removed, and FIG. In the BB arrow view, the optical fiber 1 is inserted into a pipe 12 made of metal, for example, and the optical fiber 1 and the pipe 12 on the input end side are fixed to the joint part 10 (not shown). ).

13 has a narrow diameter portion at one end into which the optical fiber 1 is loosely fitted;
This is a support member into which the pipe 12 is slidably fitted into the opening at the other end, and is fixed to the pipe 12 by a set screw 14.

The support member 13 has a diameter sufficiently large for the fiber 1 protruding from the pipe 12, and supports only the vicinity of the tip of the fiber 1 with a protrusion 13a, and the inner circumferential surface is made of, for example, a mirror surface if it is metal or a reflective film is deposited on it. It has a reflective surface due to treatment. Also, on the outer circumferential surface is a threaded portion that screws into the lens holder 16? have.

Reference numeral 16 denotes a condensing lens, which is inserted into the lens holder 16 and supported while maintaining its optical position with the output end of the optical fiber 1 by a stepped portion having a notch 161'r and a lens holder 17 made of a fireproof material. It is fixed by screwing with the member 13. Reference numeral 111L denotes the tip of the notched bead 11, which is removably fixed by tightening with a set screw (not shown) or screwing (not shown).

Does the output end side of optical fiber 1 generate 1 heat? Pipe 1 to prevent
The vicinity of the projecting output end, which projects in a free state beyond the length of the support member 13, is loosely fitted into the narrow diameter portion of the support member 13.

In this way, according to this embodiment, the narrow diameter portion 1 of the entire support member 13 near the output end protruding from the pipe 12 of the optical fiber (-1)
31L, the optical fiber 1 is regulated within the space of the narrow diameter portion 13a, and deformation due to bending or the like can be prevented.

By screwing and fixing the lens holder 16 to the support member 13, the center of the condensing lens 16 and the center of the optical fiber 1 are always on the same axis, and the laser beam irradiated from the output end of the optical fiber 1 is focused. All of the light is focused without leaving the light lens 16. Even if the optical fiber 1 and the pipe 12 are stretched due to thermal expansion, the pipe 12
The condensing lens 16 follows the elongation movement via the support member 13 and the lens holder 16, and the optical position of the output end of the optical fiber 1 and the condensing lens 16 is exactly constant.

The support member 13 does not need to be inserted after the optical fiber 1 is fully assembled, but can be fitted onto the pipe 12 in advance and slid toward the input side and temporarily secured (as shown by the two-dot chain line).
In this state, work such as end face seating can be done and the optical fiber assembly can be easily assembled without damaging it.

This is because the inner peripheral surface of the support member 13 is a total reflection surface.

Leakage light from the optical fiber 1 is reflected. Also light fa.

When the heat of the fiber 1 is transferred to the support member 13.

The contact portion of the support member 13 with the optical fiber is a protrusion 13a.
Since the contact is only slight, there is no influence on the hand piece 11, and operational safety is improved.

There are very few cases where the laser beam output angle from the output end of the optical fiber 1 becomes wider than the diameter of the condenser lens 16, and complete operation is possible.

Effects of the Invention As described above, the present invention has a stable optical position between the optical fiber and the condensing lens, which prevents the transmission efficiency from decreasing, and the operational performance is also very safe. It is especially effective for use inside the human body, such as small-diameter optical fibers (-cables) or endoscopes, and its value is enormous.

[Brief explanation of the drawing]

Figure 1 is a side cross-sectional view of a conventional optical fiber cable, Figure 2 is a perspective view of a laser irradiation device using an optical fiber cable, and Figure 3 is a side view of the output part of an optical fiber cable according to an embodiment of the present invention. The sectional view, FIG. 4 is a view taken along the line A--in the direction of the arrow in FIG. 3, and FIG. 6 is a view taken along the line BB in FIG. 3. 1°0°°"・Optical fiber, 12... Lens + 13... Support member, 16... Lens holder, 16... Condenser lens + 17.・・・・・・
・Lens holder. Name of agent: Patent attorney Toshio Nakao and one other person. Figure 1 Figure 2

Claims (1)

[Claims] (1) A protection tube that protects an optical fiber, a support member through which the protection tube is inserted and into which the optical fiber is loosely fitted, and a laser beam condensing lens provided near the output end of the optical fiber. An optical fiber cable comprising: a holding member for holding the entire condenser lens; and an engaging portion for engaging the support member and the holding member. <2) The original fiber cable according to claim 1, characterized in that the support member is made of a light reflecting member. The optical fiber cable according to claim 1, wherein a part of the supporting member has a diameter sufficiently larger than that of the optical fiber.