JPS61249002A - Detector for cutting of laser fiber - Google Patents

Abstract

PURPOSE:To detect the cutting of a fiber for the laser light instantaneously and to secure safety with simple constitution by connecting a photodetector to an end part of a light guiding fiber provided along the fiber for power laser light. CONSTITUTION:The light guiding fiber 10 is arranged in parallel to a fiber 4 for transmission which is connected to a power laser light source 1 and a condenser lens 3; and an optical sensor 11 is fitted to one end of the fiber 10 and a light shield 12 is fitted to the other. If the fiber 4 is broken at a halfway point, its coating material is burnt with the high heat of energy converged on the break point and the resulting burning of the fiber 10 is detected by the optical sensor 11 to turn on a power supply/cutoff device 9, thereby stopping laser oscillation. Thus, the breakage of the fiber 4 is detected instantaneously to prevent a fire and an accident resulting in injury or death due to power laser irradiation, thereby securing the safety with the simple structure.

Description

Detailed Description of the Invention: a. Technical Field The present invention relates to a device for detecting breakage of a power laser transmission fiber, and is applicable to industrial laser processing machines and medical devices that detect breaks and thermal damage in power laser transmission fibers. This technology is applied to laser scalpel devices, etc.

b. Conventional technology and its problems In recent years, the application of lasers to processing and treatment has been remarkable, and along with this, transmission technology using fibers has also progressed, and laser light is transmitted from a single laser device through a fiber, and it is branched to perform multi-processing. It has become increasingly common for treatments to be performed, or for processing and treatment to be performed at a location remote from the laser device.

The size of the general laser beam transmission fiber used for processing and treatment is often 0.5 to 1 mm in diameter, but there is a risk of breakage due to careless handling or accidental breakage due to animals such as rats. , accompanied by thermal damage.

If you continue to operate an industrial laser processing machine or a medical laser device under such conditions, not only will energy not be supplied to the target area, but the energy will be concentrated at the damaged part of the fiber, causing the damaged part to become extremely hot. There was a danger that it could lead to combustion, causing a fire accident or human trouble.

A device was needed to check for thermal damage, physical shock, and breakage of the transmission fiber due to damage from animals such as rats.

As a conventional example, for example, the technology disclosed in Japanese Patent Application Laid-open No. 56-40737 is shown in FIG. , is a device that irradiates a diseased area with power laser light 2 from an output end face 4b, in which a part of the power laser light 2 is reflected at the output end face 4b, and the reflected light 5 emitted from the input end face 4a is reflected by a reflection mirror 6.
And detection equipment! l! 7 and attempts to detect the state of damage at the end face of the transmission fiber 4 from abnormalities in reflected light. This device cannot detect damage in the middle of the transmission fiber.

Another conventional example is the technique disclosed in Japanese Utility Model Application No. 54-103098, in which a cuttable conducting wire 8 is arranged along the transmission fiber 4 as shown in FIG. There was a device that detected an abnormality when the conductor melted due to leakage. However, in this case, conductor 8
When transmission fiber 4 is cut because it is in a closed loop.

Since it becomes impossible to reuse it, it results in an expensive loss in terms of cost.

C1 Purpose The present invention is intended to eliminate the above-mentioned drawbacks of the conventional technology, and includes a light guiding fiber attached to a power laser transmission fiber, and an optical sensor on one end face of the fiber.
The present invention provides a device for detecting a break in a power laser transmission fiber, which is capable of detecting a break in a power laser transmission fiber simply by connecting a detector such as a solar cell, for example.

d. Structure of Embodiment An embodiment in which the present invention is applied to a medical laser device will be described based on FIG. 1.

The same parts as in the conventional example are given the same reference numerals.

FIG. 1 shows the relationship among the power laser light source device W1, the condenser lens 3, and the transmission fiber 4 that transmits the power laser light 2. As shown in FIG.

In the present invention, the power laser light source device is further connected to the power laser light source device l! A cutoff device 9 is arranged to cut off the supply of power to 1.

The transmission fiber 4 is a single fiber with a core diameter of about 0.6 mm, and light guide fibers 10 for general communication with a small diameter of about 0.02 mm are arranged in parallel along the transmission fiber 4. It is.

In FIG. 2, this is shown spirally wound around the transmission fiber 4.

As shown in Figure 1 and Figure 2, the power laser beam 2
A light sensor 11 such as a solar cell is connected to one end of the light guide fiber IO on the input end side, and a light shielding device 12 is attached to the other end of the light guide fiber 10 on the output end side.

Said optical sensor 11 is connected to a blocking device 9.

FIG. 3 shows another embodiment, in which the light guide fiber 1
Optical sensors 11 are connected to both ends of 0.

e. Effect of the Example If the fiber is broken in the middle under such a configuration, energy will be concentrated at the broken point during irradiation with the power laser beam, so the resin that is generally used for the fiber cladding material will be damaged due to high heat. Burns wood and polymeric cladding. At this time, the small diameter light guiding fiber placed along the fiber will also burn out, so the combustion light of the light guiding fiber will be detected by the optical sensor, and the signal from the optical sensor will quickly trigger a power supply cutoff device. The power laser becomes ON and the laser oscillation of the power laser light source stops. The light shielding device attached to the other end of the fiber is to prevent noise from external light. If you install optical sensors at both ends of the light guiding fiber.

Even if the light guiding fiber were to be cut, it would be detected by one of the optical sensors.

f6 Effects of the Invention As described above, the present invention eliminates the bending of the power laser two-eye bar by simply arranging flexible small-diameter fibers for general optical communication along the power laser fiber and connecting one end to the solar cell. It was created because it can instantly detect when power laser light is irradiated, preventing fire accidents and personal injury caused by power laser irradiation, and because the structure is extremely simple, it can be installed in conjunction with conventional systems. The cost is also low, and safety can be ensured when used in industrial processing machines, medical laser equipment, etc., and its practicality is extremely high.

[Brief explanation of drawings]

FIG. 1 is a diagram showing one embodiment of the present invention. FIG. 2 is a diagram showing another embodiment of the present invention. FIG. 3 is a diagram showing another embodiment of the present invention. FIG. 4 is a reverse mold. FIG. 5 is a diagram showing a conventional example. 4: Transmission fiber 9: Shutoff device 10: Light guiding fiber 11: Optical sensor 12: Light shielding device t6 times

Claims (1)

[Scope of Claims] 1. A laser fiber cutting detection device characterized in that a light guide fiber is provided along a power laser light fiber, and an end of the light guide fiber is connected to a photodetector. 2. The laser fiber cutting detection device according to claim 1, wherein the light guiding fiber is a combustible fiber. 3. The laser fiber cutting detection device according to claim 1, wherein the light guiding fiber is shielded from light at the tip end thereof relative to the photodetector.