JPH0423735B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention detects combustion caused by leakage of high-power laser light to the outside of the core due to breakage of a power transmission fiber in processing and medical laser devices. The present invention relates to a detection device for.

Conventional technology and its problems In general, the length of power transmission fibers used in medical laser scalpels, etc. is several meters, and the entire length of the fiber is visible, so the fiber may be damaged and a high-power laser Even if light leaks outside the core, it can be easily detected. However, when the length of the fiber is several tens of meters and it is routed through the walls or ceiling of a building, the middle part of the fiber may be damaged and high-power laser light may leak outside the core. Even if the coating member or the like burns, it is difficult to detect it, and there is a possibility that the laser beam will continue to be irradiated, which poses a safety problem. Conventionally, as a device for detecting fiber breakage, in consideration of the case where the fiber is passed through an endoscope, a conductor is wound around the fiber, and a breakage of the fiber is detected by checking whether the conductor is conductive or non-conductive. Although it is disclosed in Japanese Patent Publication No. 120883/1983, even if the fiber is damaged, the conductor is not always cut, and sometimes only the conductor is cut, so not only is there a lack of certainty, but the entire length of the fiber is If the length is long, it takes time and effort to manufacture, and it is not suitable for use when wiring the fiber through a wall or ceiling, etc., as described above.

Purpose The present invention has been made in view of the above-mentioned points, and is a detection device that easily and reliably detects burning of coating members, etc. due to fiber breakage in optical power transmission using fibers spanning tens of meters. The purpose is to provide

Configuration of Embodiment Hereinafter, an embodiment of the present invention will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes a laser oscillator that generates laser light, and the laser oscillator 1
A fiber 2 is attached to the fiber 2 through which a laser beam is incident from its end face by an optical system (not shown). Incidentally, the optical connection between the laser oscillator 1 and the fiber 2 is a well-known technique, and its explanation will be omitted. The fiber 2 is introduced into the metal pipe 3 from one end 3a and exits from the other end 3b. The inner wall surface of the pipe 3 is smoothed by wrapping, honing, etc., and has a high light reflectance. Also,
At one end 3a of the pipe 3, a photodetector 4 having approximately the same diameter as the inner diameter of the pipe is fixed to the pipe 3 together with a fiber 2 using an opaque material to prevent light leakage, and at the other end 3b of the pipe 3, a photodetector 4 is fixed to the pipe 3 with a fiber 2 made of an opaque material to prevent light leakage. The manufactured light shielding plate 5 is attached, and the fiber 2 comes out of the pipe through a hole provided approximately in the center of the light shielding plate 5.
The photodetector 4 is connected to a signal processing circuit 7 via a signal line 6, and the signal processing circuit 7 is further connected to the laser oscillator 1 via a signal line 8. Further, the pipe 3 is disposed through walls 9 and 10 of a building that separate the location where the laser oscillator 1 is installed and the location where processing, treatment, etc. are actually performed using laser light.

Effects of the Embodiment Next, the effects of the embodiment of the present invention having the above configuration will be explained.

If the fiber 2 is damaged inside the metal pipe 3 and high-power laser light leaks out of the fiber core, the coating material of the fiber absorbs the laser light and is heated and burned. The light generated during this combustion reaches the photodetector 4 either directly or while repeatedly reflecting on the inner surface of the pipe 3. The photodetector 4 generates an electrical output corresponding to the optical input,
The signal is sent to the signal processing circuit 7. The signal processing circuit 7 compares the electrical output from the photodetector 4 with a set level, and if the input is greater than the set level, it issues a signal to the laser oscillator 1 to stop laser oscillation.

Although the pipe 3 is substantially straight in the embodiment shown in the first figure, the same effect can be obtained even if it has a bent part, and the photodetector 4 and signal processing circuit 7 can be arranged at both ends of the pipe 3. Of course, the reliability will be further increased. Furthermore, it is also possible to input the output signal from the signal processing circuit 7 to a well-known fire extinguishing means so as to not only stop the laser oscillation of the laser oscillator 1 but also actively extinguish the fire.

Effects As described above, according to the present invention, with a simple configuration, it is possible to reliably detect burning of covering members, etc. due to damage to fibers, especially when wiring fibers through walls, ceilings, etc. It has a big effect. Furthermore, the output signal of the detection device of the present invention can be easily used as a stop signal for a laser oscillator or a start signal for a known fire extinguishing means.
There is no danger of continuing to operate the laser oscillator without knowing that the fiber will be damaged, and this greatly contributes to increasing safety when using the laser device.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of one embodiment of the present invention. 1... Laser oscillator, 2... Fiber, 3
...Pipe (fiber guide tube), 4...Photodetector, 7...Signal processing circuit.

Claims (1)

[Claims] 1 A fiber guide tube containing a fiber that transmits optical power from a laser oscillator and whose inner surface is processed to enhance light reflection, and a fiber guide tube disposed at at least one end of the fiber guide tube that transmits an electric signal according to the amount of incident light. Combustion detection of a power transmission unit in a laser device equipped with a photodetector that generates light and a signal processing circuit that compares the output of the photodetector with a set value and outputs an electric signal when the output of the photodetector is large. Device.