JPH04130784A - Laser system - Google Patents

Abstract

PURPOSE:To shorten the time to take for making an excitation lamp light at the time of start of the operation of a laser main body as well as to reduce a time lag at the time of starting of a laser to contrive the improvement of the starting performance of the laser by a method wherein at the time of starting of the lighting of the excitation lamp, a cooling liquid having a high electric resistance value is supplied in a solid laser resonator from an auxiliary cooling liquid supply part. CONSTITUTION:At the time of starting of a laser, a first on-off valve 21 is first operated in a OFF-state and at the time same time, a second on-off valve 23 is opened. In this state, a pump 11 is driven and a cooling liquid in a cooling liquid tank 10 is introduced in a condensing device 4 via the lamp 11, a filter 12, a bypass path 22, the valve 23 in this path 22 and an auxiliary tank 24. In this case, as a cooling liquid, such as pure water or the like, in the tank 24 is held in a state that its electric resistance value is high, the cooling liquid having the high electric resistance value is introduced in the device 4. By the introduction of this cooling liquid, a power circuit 29 is opened in a state that the electric resistance value of the cooling liquid on the periphery of an excitation lamp 3 in the device 4 is made high and the lamp 3 is lighted. Thereby, at the time of start of the operation of the laser main body, the time to take for making the lamp 3 light can be shortened compared to the case of a conventional constitution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser device that circulates a cooling liquid within a condenser.

[Prior Art] Generally, as a laser device, for example, Japanese Patent Application Laid-open No. 6 O-B396
The configuration shown in Publication No. 3 is disclosed.

This device has a configuration in which a portion of a coolant flow path is disposed within the laser oscillator, and the laser oscillator is cooled by the coolant, such as pure water, in the coolant flow path.

Further, as a cooling means for a laser oscillator, a structure shown in FIG. 4 is conventionally known. In FIG. 4, 1 is a solid-state laser resonator. In this solid-state laser oscillator, a laser rod 2 and an excitation lamp 3 are installed so as to be immersed in a cooling liquid in a condenser 4. This laser rod 2
On the axis of the laser rod 2, a first resonant mirror 5a and a second resonant mirror 5b are arranged on one side of the laser rod 2 and on the other side of the rod 2, facing each other and spaced apart from each other. Furthermore, the excitation lamp 3 is connected to a power supply circuit 6.

Further, the condenser 4 is provided with an inlet lower a and an outlet lower b for the coolant, and both ends of the coolant passage 8 are connected to the inlet lower a and the outlet lower b. A heat exchanger 9, a coolant tank 10, a bomb 11, and a filter 12 are connected to the coolant passage 8 in this order from the output lower b side of the condenser 4. Furthermore, one end portion of a bypass passage 14 having an ion exchanger 13 interposed therebetween is connected to the coolant tank 10 . The other end of this bypass passage 4 is connected between a pump 11 and a filter 12 in a coolant passage 8 .

On the other hand, 15 is a controller of this laser device formed by, for example, a microcomputer and its peripheral circuits. An electric resistance measuring device 16 for measuring the electric resistance of the coolant is connected to the controller 15, and a power supply circuit 6 for the excitation lamp 3 and a pump]1 are also connected to the controller 15. Furthermore, the resistance measuring device 16 includes a first resistance measuring element 16a disposed in the coolant tank 10.
and a second resistance measuring element 16b disposed on the entrance lower a side of the condenser 4 in the coolant passage 8.

The controller 15 controls the operation of the laser device as follows. When starting up this laser device, first the pump 11 is driven. As the pump 11 is driven, the coolant in the coolant tank 10 is introduced into the condenser 4 through the pump 11 and the filter 12 as shown by the arrow in FIG. It is adapted to cool the rod 2 and the excitation lamp 3. Further, the cooling liquid applied from the specific lower part b of the condenser 4 is cooled by a fan in the heat exchanger 9, and then
The coolant is collected in the coolant tank 10.

Further, a part of the coolant sucked out from the coolant tank 10 by the pump 11 is introduced into the ion exchanger 13, where the ions are exchanged and the electrical resistance value is increased. The coolant is allowed to flow into the coolant tank 10 again.

Further, while the laser device is in operation, a resistance measuring device 16 detects the electrical resistance value of the coolant, that is, pure water.

In this case, the coolant contains ions, and when the ion concentration is high, electricity easily flows into the coolant, that is, the electrical resistance value of the coolant becomes small. Here, if the electrical resistance value of the coolant is smaller than a predetermined set value, even if the power supply circuit 6 is turned on, current flows through the coolant and the excitation lamp 3 cannot be turned on. Therefore, when it is detected that the electrical resistance value of the coolant is equal to or higher than a predetermined set value, the power supply circuit 6 is turned on and the excitation lamp 3 is turned on. By lighting the excitation lamp 3, energy is given to the laser rod 2, which is excited and outputs laser light.

[Problems to be Solved by the Invention] Generally, when the laser rod 2 and excitation lamp 3 of the solid-state laser resonator 1 are installed in a state where they are immersed in the cooling liquid in the condenser 4, the cooling liquid If the ion concentration in the coolant is high and the electrical resistance of the coolant is small, there is a problem in that the excitation lamp 3 does not light up even if the power supply circuit 6 is turned on. In this case, the coolant tank 1 disposed in the coolant passage 8
Components such as No. 0 are made of metal materials, and metal ions tend to accumulate in the coolant, so there is a problem in that the ion concentration tends to increase. Therefore, when the laser device starts operating, the ion concentration in the coolant is often maintained at a high level, so it takes time for the electrical resistance value in the coolant to increase due to ion exchange in the ion exchanger 13. There was a problem that the lighting of the excitation lamp 3 was delayed.

It is also conceivable to directly interpose the ion exchanger 13 in the coolant passage 8 to increase the ion exchange efficiency and shorten the time it takes to increase the electrical resistance value in the coolant. However, when the coolant is passed through the ion exchange resin, the pressure loss is large, so when the ion exchanger 13 is directly interposed in the coolant passage 8, the coolant in the coolant passage 8 is The flow resistance increases, and the laser rod 2 and excitation lamp 3 are immersed in the cooling liquid in the condenser 4.
There is a problem that the cooling efficiency of the system decreases. Therefore, there was a problem in that the ion exchanger 13 could only be directly interposed within the coolant passage 8.

This invention was made in view of the above-mentioned circumstances, and it is possible to shorten the time it takes to turn on the excitation lamp when the device main body starts operating, thereby reducing the time lag at the time of starting and improving starting performance. The object of the present invention is to provide a resa device.

[Means for Solving the Problems] The present invention includes a laser lot, an excitation lamp, a solid-state laser resonator installed in a state of being immersed in a cooling liquid in a condenser, and a combination of the condenser and a heat exchanger. In a laser apparatus in which a coolant passage is provided between which a coolant is circulated, and an ion exchanger for increasing the electrical resistance of the coolant is connected to the coolant passage, the coolant passage is located upstream of the solid-state laser resonator. An auxiliary coolant supply section is provided on the side for supplying a coolant having a high electrical resistance value only when the excitation lamp starts lighting.

[Function] By supplying a coolant with a high electrical resistance value into the solid-state laser resonator from the auxiliary coolant supply section when the excitation lamp starts lighting, the time it takes to turn on the excitation lamp when the main unit starts operating is shortened. This is designed to reduce the time lag during startup.

[Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 shows a schematic configuration of the entire laser device. Note that in FIG. 1, the same parts as in FIG. 4 are designated by the same reference numerals, and the explanation thereof will be omitted.

In the laser device of this embodiment, a first valve is formed by, for example, a solenoid valve in a passage portion between the input lower a of the condenser 4 and the filter 12, which is the upstream side of the solid-state laser resonator 1 in the coolant passage 8. An on-off valve 21 is provided. Furthermore, a bypass passage 2 is provided in parallel with this first on-off valve 21.
2 are connected to each other, and a second on-off valve 23 formed by, for example, a solenoid valve and an auxiliary tank (auxiliary coolant supply section) 24 formed by an ion exchanger are interposed in this bypass passage 22, respectively. There is.

In this case, the second on-off valve 2B is arranged on the filter 12 side in the bypass passage 22, and the auxiliary tank 24 is arranged on the condenser 4 side in the bypass passage 22.

Furthermore, an ion exchange resin 25 is housed in the auxiliary tank 24 . This ion exchange resin 25 is in the auxiliary tank 2.
It is always in contact with the coolant in the auxiliary tank 24, and the coolant such as pure water in the auxiliary tank 24 is maintained at a high electrical resistance value.

In addition, the first on-off valve 21 and the second on-off valve 2
3 is connected to a controller 26 of this laser device formed by, for example, a microcomputer and its peripheral circuits. A first temperature sensor 27 disposed in the coolant tank 10 and a second temperature sensor 28 disposed on the outlet side of the filter 12 in the coolant passage 8 are connected to the controller 26, respectively. A power supply circuit 29 for the excitation lamp 3 and the pump 11 are also connected to the controller 26, and the operation of the laser device is controlled by the controller 26. In addition, power supply circuit 2
9 shows a switch for turning on and off the excitation lamp 3, and a state in which the energizing current of the excitation lamp 3 is set to a normal first set value aA and a second set value bA that is smaller than the first set value aA. Each has a built-in energizing current switching circuit that switches between the two.

Next, the operation of the above configuration will be explained.

When starting up this laser device, first the first on-off valve 21
is operated to close, and at the same time, the second on-off valve 23 is operated to open. Then, in this state, the pump 11 is driven,
As the pump 11 is driven, the coolant in the coolant tank 10 flows through the pump 11, the filter 12, and the bypass passage 22.
and a second on-off valve 23 in this bypass passage 22
, is introduced into the condenser 4 via the auxiliary tank 24. In this case, since the coolant such as pure water in the auxiliary tank 24 is maintained in a state with a high electrical resistance value, the coolant with a high electrical resistance value is introduced into the condenser 4 . Furthermore, the power supply circuit 29 is turned on while the electrical resistance of the cooling fluid around the excitation lamp 3 in the condenser 4 is increased by introducing the cooling fluid with a high electrical resistance value supplied from the auxiliary tank 24. Excitation lamp 3 is turned on.

After the excitation lamp 3 is turned on, the first on-off valve 21 is opened and the second on-off valve 23 is closed to perform normal operation. In this state, as the pump 11 is driven, as shown by the arrow in FIG.
2. The light is introduced into the condenser 4 through the first opening/closing valve 21, and the nozzle rod 2 and excitation lamp 3 within the condenser 4 are cooled. Furthermore, the coolant flowing out from the output lower b of the condenser 4 is cooled by a fan through a heat exchanger 9, and then collected into a coolant tank 10, and is then pumped from within the coolant tank 10 by a pump 11. A portion of the coolant that has been sucked out is introduced into the ion exchanger 13, where ions are exchanged within the ion exchanger 13, and the electrical resistance is increased, and then the coolant flows into the coolant tank 10 again.

Also, during normal operation of the laser device, the first temperature sensor 27
A detection signal from the second temperature sensor 28 is input to the controller 26, and based on this detection signal, the controller 26 performs the following overheat prevention control.

That is, as shown in FIG. A set value aA and a second set value bA smaller than the normal state are each stored in advance. After the laser apparatus is started, the power supply circuit 29 is controlled by the controller 26 during normal operation so that the current flowing through the excitation lamp 3 is maintained at the normal first set value aA.

Further, when it is detected that the detected temperature of the coolant in the coolant passage 8 detected by the temperature sensors 27 and 2B has increased by the upper set temperature B'C, the current flowing through the power supply circuit 29 at this time point t1. The switching circuit is operated to switch the energizing current of the excitation lamp 3 to the second set value bA. In this case, the amount of heat generated by the excitation lamp 3 decreases, so the temperature of the coolant in the coolant passage 8 gradually decreases. Then, at the time t2 when it is detected that the detected temperature of the coolant in the coolant passage 8 detected by the temperature sensors 27 and 28 has decreased to the lower set temperature A°C, the energizing current switching circuit of the power supply circuit 29 is switched again. The switching operation is performed to the original normal state, and the current flowing through the excitation lamp 3 is switched to the first set value aA.

Further, it is detected that the detected temperature of the coolant in the coolant passage 8 has increased abnormally due to some abnormality such as stopping of the cooling fan of the heat exchanger 9, and has reached the interlock set temperature C°C. Then, at time t3, the power supply circuit 29 is turned off, and the current flowing through the excitation lamp 3 is cut off.

Therefore, in the above configuration, when the excitation lamp 3 starts lighting, a coolant with a high electrical resistance value is supplied from the auxiliary tank 24 into the solid laser resonator 1, and the electric resistance of the coolant around the excitation lamp 3 is Since the excitation lamp 3 is turned on by turning on the power supply circuit 29 while the value is increased, the time required to turn on the excitation lamp 3 at the start of operation of the apparatus main body can be shortened compared to the conventional method. Therefore, it is possible to reduce the conventional time lag during startup and improve the startup performance of the laser device.

Furthermore, since the controller 26 performs overheat prevention control, the temperature of the coolant in the coolant passage 8 is lowered to the lower set temperature A'C during normal operation of the laser device.
and the upper set temperature B'C. Therefore, it is possible to reduce the number of times that the laser light output completely stops during normal operation of the laser device, so for example, when applied to a medical laser device, it is possible to prevent surgery from being interrupted. can. Further, when it is detected that the temperature of the coolant in the coolant passage 8 has increased abnormally and reached the ink clock set temperature C'C, the power supply circuit 29 is turned off at time t3, and the excitation lamp 3 is turned off.
Since the energizing current is cut off, the coolant passage 8
It is possible to prevent the coolant in the coolant passage 8 from leaking due to an abnormal rise in the temperature of the coolant in the coolant passage 8, thereby preventing electric leakage from occurring.

Further, FIG. 3 shows a second embodiment of the invention.

In this embodiment, an auxiliary tank (auxiliary coolant supply section) 32 containing an ion exchange resin 31 is provided, and the coolant is stored in this auxiliary tank 32.

Furthermore, a first opening/closing valve 33 formed by a solenoid valve, for example, is interposed in a passage portion between the filter 12 and the input lower a of the condenser 4, which is the upstream side of the solid-state laser resonator 1 in the coolant passage 8. It is set up.

Further, one end of a bypass passage 34 is connected to the auxiliary tank 32 . A pump 35 and a second on-off valve 36 formed by, for example, a solenoid valve are interposed in this bypass passage 34. And this bypass passage 34
The other end is connected between the entrance lower a of the condenser 4 of the solid-state laser resonator 1 in the coolant passage 8 and the first opening/closing valve 33 .

In addition, the first on-off valve 33 and the second on-off valve 3
6 is connected to a controller 26 of this laser device formed by, for example, a microcomputer and its peripheral circuits.

When starting up this laser device, first the first on-off valve 33 is operated to close, and the second on-off valve 33 is operated to close.
6 is operated to open. Furthermore, the pump 35 is driven in this state, and as the pump 35 is driven, the auxiliary tank 3
A cooling liquid having a high electrical resistance value is introduced into the condenser 4 . At this time, the pump 11 is held in a stopped state. Then, the power supply circuit 29 is turned on while the electrical resistance of the cooling fluid around the excitation lamp 3 in the concentrator 4 is increased by introducing the cooling fluid with a high electrical resistance supplied from the auxiliary tank 32. Excitation lamp 3 is turned on.

Further, after the excitation lamp 3 is turned on, the first on-off valve 33 is opened, the second on-off valve 36 is closed, and at the same time the pump 35 is stopped to perform normal operation. In this state, as the pump 11 is driven, as shown by the arrow in FIG.
The laser rod 2 and the excitation lamp 3 in the condenser 4 are cooled. Furthermore, the coolant flowing out from the output lower b of the condenser 4 is cooled by a fan in the heat exchanger 9, and then collected into the coolant tank 10. A portion of the coolant that has been sucked out is introduced into the ion exchanger 13, where ions are exchanged within the ion exchanger 13, and the electrical resistance is increased, and then the coolant flows into the coolant tank 10 again.

Therefore, even with the above configuration, when the excitation lamp 3 starts lighting, a coolant with a high electrical resistance value is supplied from the auxiliary tank 32 into the solid laser resonator 1, and the electric resistance of the coolant around the excitation lamp 3 is Since the excitation lamp 3 is turned on by turning on the power supply circuit 29 while the value is increased, the same effect as in the first embodiment can be obtained.

It should be noted that this invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the invention.

[Effects of the Invention] According to the present invention, an auxiliary coolant supply section is provided on the upstream side of the solid laser resonator in the coolant passage to supply a coolant having a high electrical resistance value only when the excitation lamp starts lighting. The time required to turn on the excitation lamp at the start of operation of the main body can be shortened, the time lag at the time of starting can be reduced, and starting performance can be improved.

[Brief explanation of drawings]

Figures 1 and 2 show a first embodiment of the present invention. Figure 1 is a schematic diagram of the entire laser device, and Figure 2 shows the state of change in excitation lamp current due to temperature control by the controller. Characteristic diagrams for explanation; FIG. 3 is a schematic configuration diagram of the entire laser device showing a second embodiment of the present invention; FIG. 4 is a schematic configuration diagram of the entire conventional laser device. 1... Solid laser resonator, 2... Laser rod, 3
...Excitation lamp, 4...Concentrator, 8...Cooling liquid passage, 9...Heat exchanger, 13...Ion exchanger, 24
゜32... Auxiliary tank (auxiliary coolant supply section). Applicant's representative Patent attorney Atsushi Tsuboi 1st, 2nd and 4th

Claims (1)

[Claims] A solid-state laser resonator in which a laser rod and an excitation lamp are installed in a state where they are immersed in a cooling liquid in a condenser, and a cooling liquid is provided between the condenser and a heat exchanger. In the laser device, a coolant passage for circulation is provided, and an ion exchanger for increasing the electrical resistance of the coolant is connected to the coolant passage. 1. A laser device comprising an auxiliary coolant supply section that supplies a coolant having a high electrical resistance value only when lighting starts.