JP3385189B2 - Laser oscillator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser oscillation device, more specifically, the output of a part of pulsed laser light emitted from a laser oscillator in real time. The present invention relates to a laser oscillation device provided with a so-called power sensor in order to measure and constantly monitor missing of a laser beam pulse. Conventionally, for example, a sheet-like shape such as a through hole (through hole) of a printed circuit board, an air hole of a cigarette paper, or a perforated continuous hole for facilitating separation of various slips. When a small-diameter through hole is drilled in the base material, it is common to use mechanical processing performed using a sharp drilling tool such as a drill. However, in such a mechanical processing method, there is a limit to reducing the diameter of the processed hole, and it is actually difficult to further increase the processing speed. Furthermore, there is a problem that is unavoidable for a mechanical processing method using a tool, in which the tool is worn or damaged as processing is repeated. Therefore, instead of such a mechanical processing method, a processing method using a pulse laser beam is rapidly spreading. According to this laser processing method, a finer hole can be formed with high accuracy and at a higher speed. FIG. 2 schematically shows an example of a processing system using this laser beam. As shown in this figure, the pulsed laser light L emitted from the laser oscillator 1 passes through the partial transmission mirror 2 and most of the (La) is fixed to the swing shaft 7 of the galvanometer 6. 8 leads. The laser beam La reflected by the reflecting mirror 8 is incident on the condenser lens 9 and then condensed on a predetermined point on the sheet St. At this condensing point, the energy density is extremely high, and the laser light instantly melts and sublimates the minute portion of the sheet material to open a minute hole. And the galvanometer 6
Is changed by changing the angle of the reflecting mirror 8
1, P2, P3,... And minute holes are continuously machined from the left side to the right side in FIG. However, even in such a processing method using pulsed laser light, the emission time of laser light per pulse is usually as short as 1 millisecond or less, and the performance of the laser oscillator 1 deteriorates over time. In some cases, the pulse laser beam may be lost or the energy intensity may be insufficient. In such a case, a predetermined hole cannot be formed in the sheet, and a defect occurs in the processed product. Therefore, in order to detect such defects as early as possible, a power sensor that measures the output of the pulsed laser light emitted from the laser oscillator in real time and constantly monitors the lack of pulsed laser light and insufficient energy intensity for the command. It is considered to equip. That is, the laser oscillation device 1 shown in FIG.
In 0, a part Lb of the laser beam L emitted from the laser oscillator 1 (usually about 5% of the entire laser beam L) is reflected by the partial transmission mirror 2 and guided to the condensing lens 3, and then the power sensor. 11 light receiving portions 11a. Then, an electrical signal G proportional to the energy of the received laser beam Lb
s is sent to the control unit 13 and is constantly monitored in real time during operation of the apparatus 10. As the power sensor 11, a sensor having a very high responsiveness is usually used, and an electric signal Gs similar to the waveform of the received pulsed laser beam energy is output. The control unit 13 instantaneously compares the laser beam emission command signal and the electric signal Gs from the power sensor 11, and if there is a difference between them, the control unit 13 notifies the operator as an abnormality by an alarm signal or the like. Action is to be taken. The power sensor 11 includes a light receiving unit 11.
In order to prevent damage due to excessive temperature rise of a, the vicinity thereof is cooled by water or oil. The average power of the laser light collected in the light receiving unit 11a is determined by the laser oscillation device 1
At the time of normal use of 0, for example, it is sufficiently small, for example, about 1 to 2 watts, so that the temperature rise is suppressed within a certain range by the above cooling. This is because the pulse laser beam emission time is extremely short, and the pause time is sufficiently long. However, the laser oscillation device 10 needs to be inspected and maintained at regular intervals in order to maintain its performance, and during adjustment after this inspection, a high-power laser is required. A continuous light wave may be emitted. In this case, the power sensor 11 has, for example, 20
A laser beam with a large output exceeding watts is directed, and when the power sensor 11 receives the light as it is, the light receiving portion 11a is damaged due to an excessive temperature rise. For this reason, at the time of adjustment after inspection of the apparatus, it is necessary to remove at least one of the power sensor 11 and the partial transmission mirror 2 to prevent high-power laser light from entering the light receiving unit 11a of the power sensor 11. there were. However, when the power sensor 11 or the partial transmission mirror 2 is once removed and then reattached, it is necessary to precisely adjust the position and angle. There was a problem that it took time and effort. Also, at the time of adjustment after the above equipment inspection, for example, due to an inadvertent mistake of the adjustment operator,
It has been experienced in the past that the power sensor 11 is broken when the power sensor 11 and the partial transmission mirror 2 are not removed, and a high-power continuous laser beam is emitted. It is strongly desired to ensure that the power sensor 11 can be prevented from being damaged even when a mistake or the like occurs. The present invention has been made in view of the technical problems in the conventional laser oscillation apparatus as described above. The power required for adjustment after inspection of the apparatus can be obtained only by adding a simple configuration. It is an object of the present invention to make it possible to omit the attaching / detaching operation of the sensor or the partial transmission mirror and to reliably prevent the power sensor from being damaged during the adjusting operation of the laser oscillator. For this reason, a laser oscillation apparatus according to the present invention comprises a laser oscillator that emits laser light, and transmits most of the laser light emitted from the laser oscillator and transmits the remaining light. a partial transmission mirror for reflecting part, the laser beam reflected by the portion <br/> partial transmission mirror and a power sensor for measuring the output power shielding means of the laser beam intercepts the laser beam Rutotomoni openable and closable with respect to the incident light path to the sensor, the laser oscillator, before
The incident optical path to the power sensor is closed by the shielding means.
Only when the specified value exceeds the preset value.
It is characterized by being controlled so as to be able to oscillate high-power laser light . DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. As shown in FIG.
The laser oscillation device 30 according to the present embodiment includes a laser beam L
And a partial transmission mirror 20 that transmits most of the laser light L emitted from the laser oscillator 32 and reflects the remaining part Lb (for example, about 5% of the entire laser light L). And a power sensor 22 for receiving the laser beam Lb reflected by the partial transmission mirror 20 and measuring its output (energy intensity). Also,
Between the power sensor 22 and the partial transmission mirror 20,
A condensing lens 21 for condensing a part of the laser light Lb reflected by the partial transmission mirror 20 toward the light receiving portion 22a of the power sensor 22 is disposed. The laser oscillation device 30, the partial transmission mirror 20, the condensing lens 21 and the power sensor 22 are all basically the same as those according to the conventional example shown in FIG. The laser oscillator 30 includes a control unit 27 for controlling a laser oscillator 32, as will be described later.
A numerical control device 31 is provided that supervises the overall control of the laser oscillation device 30. A laser beam emission command is sent from the numerical control device 31, and during normal machining operation, the laser oscillator 32 is passed through the control unit 27 as it is.
Is input. Most of the laser light La that has passed through the partial transmission mirror 20 is guided to a reflecting mirror 38 fixed to a swing shaft 37 of a galvanometer 36. The laser beam La reflected by the reflecting mirror 38 enters the condensing lens 39 and is then condensed at a predetermined point on the sheet St. At this condensing point, the energy density is extremely high, and the laser light instantaneously melts and sublimates the minute portion of the sheet material, and opens a minute hole of a predetermined size on the sheet St. Then, by swinging the galvanometer 36 and changing the angle of the reflecting mirror 38, the minute holes are continuously processed from the left side to the right side in the points P1, P2, P3,. after that,
Move the sheet St in a direction perpendicular to the paper surface in FIG.
In the same manner as described above, minute holes are continuously processed from the left side to the right side in FIG. By repeating the above steps, a large number of minute holes of a predetermined size are processed at a very high speed at each predetermined position of the sheet St. The galvanometer 36 (including its swinging shaft 37), the reflecting mirror 38, and the condenser lens 39 are basically the same as those according to the conventional example shown in FIG. The drilling process is basically the same as in the conventional example described with reference to FIG. In the present embodiment, a shielding plate 23 serving as a shielding means for shielding laser light is opened and closed with respect to the incident light path of the laser light Lb to the power sensor 22 between the condenser lens 21 and the power sensor 22. It is provided as possible. That is, the shielding plate 23 is not specifically shown,
For example, when it is reciprocated in the left-right direction in FIG. 1 by driving means such as a cylinder device or manually, and moved to the right (the state shown in FIG. 1)
When the laser beam Lb is moved to the left, the incident light path of the laser beam Lb to the power sensor 22 is closed and the laser beam Lb is blocked from entering the power sensor 22.
The incident light path to the power sensor 22 b is opened, and the laser light Lb is incident on the light receiving portion 22 a of the power sensor 22. The power sensor 22 is cooled in the vicinity by water or oil in order to prevent the light receiving portion 22a from being damaged due to an excessive temperature rise. The average power of the laser light collected in the light receiving unit 22a is determined by the laser oscillation device 3
At the time of normal use of 0, for example, it is sufficiently small, for example, about 1 to 2 watts, so that the temperature rise is suppressed within a certain range by the above cooling. This is because the pulse laser beam emission time is extremely short, and the pause time is sufficiently long. Note that the driving means such as the cylinder device of the shielding plate 23 or the manual opening / closing operation is performed by, for example, a maintenance adjustment operator. A magnet 24 is attached to one end side (left end side in FIG. 1) of the shielding plate 23, and a magnetic switch 25 is opposed to the surface of the shielding plate 23 on which the magnet 24 is attached. It is fixed. This magnetic switch 25
Is the state in which the shielding plate 23 is moved to the right in FIG. 1 (the incident light path of the laser beam Lb to the power sensor 22 is closed as shown in FIG. 1).
4 is positioned so as to face 4. At this time, the internal contact of the magnetic switch 25 is closed. On the other hand, in the state where the shielding plate 23 is moved to the left in FIG. 1 (the state where the incident light path of the laser beam Lb to the power sensor 22 is opened), the magnet 24 is separated from the magnetic switch 25. The internal contact of the magnetic switch 25 is open. The magnetic switch 25 is connected to the control unit 2.
7, the control unit 27 can recognize the open / closed state of the shielding plate 23 based on the state of the internal contact of the magnetic switch 25. When the laser oscillation device 30 is in a normal processing operation state, the shielding plate 23 is moved to the left in FIG. 1, and therefore the incident light path of the laser beam Lb to the power sensor 22 is opened. It is in the state that was. Then, a part L of the laser light L emitted from the laser oscillator 32
b is reflected by the partial transmission mirror 20, guided to the condenser lens 21, and then collected in the light receiving part 22 a of the power sensor 22. Then, an electrical signal Gs proportional to the energy of the received laser beam Lb is sent to the control unit 27, and is constantly monitored in real time during the processing operation of the apparatus 30. The power sensor 22 has a very high responsiveness, and outputs an electric signal Gs similar to the waveform of the received pulsed laser beam energy. The control unit 27 receives the laser beam emission command signal from the numerical controller 31 and the power sensor 2.
The electric signal Gs from 2 is instantaneously compared, and if there is a difference between them, the operator is notified by an alarm signal or the like as an abnormality, and necessary measures are taken. The operation of the laser oscillation device 30 in the above-described normal machining operation state is basically the same as that in the conventional example described with reference to FIG. On the other hand, at the time of adjustment accompanying maintenance of the laser oscillation device 30, the shielding plate 23 is moved to the right as shown in FIG. 1, and the incident optical path of the laser beam Lb to the power sensor 22 is as follows. It is in a closed state.
Accordingly, the laser light Lb that is reflected by the partial transmission mirror 20 and then condensed by the condenser lens 21 and directed toward the power sensor 22 is blocked by the shielding plate 23 and enters the light receiving portion 22a of the power sensor 22. Never do. as a result,
Even when a high-power continuous laser beam is emitted during adjustment of the laser oscillator 32, the shielding plate 23 closes the incident optical path of the laser beam Lb to the power sensor 22 in advance. The laser beam Lb is not incident on the light receiving portion 22a, and the expensive power sensor 22 is not damaged by an excessive temperature rise as in the prior art. Thus, the shielding plate 23 is provided with the laser beam L.
b is provided so as to be openable and closable with respect to the incident optical path to the power sensor 22, so that when adjusting the laser oscillator 32 during the maintenance of the laser oscillation device 30, the adjustment operator must remove the shielding plate 23. Only a very simple operation of closing is required. That is, the work of attaching and detaching the partial transmission mirror 20 or the power sensor 22 and the reattachment thereof, and the subsequent work of adjusting the position or angle, which are conventionally required when adjusting the laser oscillator 32, are unnecessary, and are required for maintenance. Time and labor can be greatly reduced. In the present embodiment, the laser oscillator 32 is used only when the incident light path of the laser beam Lb to the power sensor 22 is closed by the shielding plate 23.
Control is made so as to enable oscillation of a laser beam having a high output exceeding a predetermined value. That is, the control unit 27
When the incident light path of the laser beam Lb to the power sensor 22 is closed by the shielding plate 23 (when the magnetic switch 25 is closed), the laser sent from the numerical controller 31 The light emission command is input to the laser oscillator 32 as it is, and the laser beam corresponding to the command is emitted. However, when the incident optical path is open (when the magnetic switch 25 is in the open state), the laser beam emission command sent from the numerical control device 31 is less than a preset specified value. In the same manner as described above, the laser beam emission command is input to the laser oscillator 32 as it is. However, when a laser beam emission command having a higher output than the specified value is sent, the laser beam emission command is sent to the laser oscillator 3.
The alarm signal is returned to the numerical control device 31 to notify the operator that an abnormal command has been issued by means such as a display / alarm. Therefore, even if the adjustment operator forgets to close the shielding plate 23 at the time of maintenance, the high-power laser beam is not emitted from the laser oscillator 32, and the power sensor 22 is surely connected. Protected. The prescribed value is based on the output value of the laser beam that does not excessively increase the temperature of the light receiving unit 22a even if the laser beam is incident on the light receiving unit 22a of the power sensor 22, and thus does not cause damage. It is determined. In this embodiment, the shielding plate 23 slides in a direction orthogonal to the incident light path of the laser beam Lb to the power sensor 22 and reciprocates to open and close the incident light path. However, instead of this, it is also possible to provide a shielding means for performing a turning operation to open and close the incident light path. Thus, it goes without saying that the present invention is not limited to the above embodiments, and various improvements or design changes can be made without departing from the scope of the invention. According to the present gun onset light according to the present invention, since the shielding means for shielding the laser beam is provided to be openable and closable with respect to the incident light path to the power sensor of the laser beam, when maintenance of the laser oscillator When adjusting the laser oscillator, the adjustment operator only needs to perform an extremely simple operation of closing the shielding plate. In other words, the time and labor required for maintenance are no longer required for the attachment and detachment of the partial transmission mirror or power sensor, the reattachment, and the subsequent adjustment of the position or angle, which were conventionally required when adjusting the laser oscillator. Can be greatly shortened. Only
In addition, the laser oscillator enters the power sensor.
Only when the light path is closed by the shielding means
Oscillation of high-power laser light exceeding the preset value
Example, during maintenance.
For example, if the adjustment operator forgets to close the shielding plate
Even if the
No light oscillates, ensuring damage to the power sensor
Can be prevented. [0025]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall configuration diagram showing an outline of a laser oscillation apparatus according to an embodiment of the present invention. FIG. 2 is an overall configuration diagram showing an outline of a laser oscillation device according to a conventional example. DESCRIPTION OF SYMBOLS 20 ... Partially transmissive mirror 22 ... Power sensor 23 ... Shielding plate 27 ... Control unit 30 ... Laser oscillator 31 ... Numerical controller 32 ... Laser oscillator L ... Laser light La emitted from laser oscillator ... Partially transmitted Most of the laser light Lb that is transmitted through the mirror, part of the laser light that is reflected by the partial transmission mirror

─────────────────────────────────────────────────── ─── Continued from the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01S 3/00-3/30

Claims (1)

(57) Patent Claims 1. A laser oscillator for emitting a laser beam, before
Includes serial and partially transmissive mirror for reflecting a portion of the remaining is transmitted through the majority of the laser light emitted from the laser oscillator, and a power sensor for measuring the output for the laser beam reflected by the partial transmission mirror , Rutotomoni shielding means for shielding the laser beam is openably provided to the incident light path to the power sensor of a laser beam, said laser oscillator, said power
-The incident optical path to the sensor is closed by the shielding means.
Output only when the preset value exceeds the preset value.
The laser oscillation device controlled so that the laser beam can be oscillated.