JP2001212686A - Laser beam radiating optical system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam radiating optical system in which an easy observation of a processed point is possible, an entire size of the laser beam radiating optical system can be miniaturized and both of a performance and operability can be improved. SOLUTION: A laser beam radiating optical system in which an optical system for irradiating a laser beam is built in a casing is provided with a roof- shaped prism 20-1 for dividing an incident laser beam, and a focusing lens 14 for irradiating the laser beam through the roof-shaped lens to a work as elements of the optical system. The roof-shaped prism and focusing lens are arranged on the same optical axis. Further, on the optical axis between the roof-shaped prism and focus lens, a first mirror 10 is also arranged so that a laser beam from the roof-shaped prism is permeated and a visible light from the work is reflected. An observation optical system including a CCD camera 15 to observer the area including the work by receiving a reflected light from the first mirror is further provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser emission optical system for irradiating a laser beam for processing onto a workpiece, and more particularly to irradiating the laser beam on the workpiece in a divided manner or forming a circular locus on the workpiece. The present invention relates to a laser emission optical system including a prism for rotating and irradiating in a drawing manner.

[0002]

2. Description of the Related Art There have been proposed various types of laser processing apparatuses for making a hole in a printed wiring board or a ceramic substrate or welding a metal plate using a laser beam such as a YAG laser beam.

[0003] In such a laser processing apparatus, laser light from a laser oscillator is guided to a laser emission optical system by an optical fiber. As shown in FIG. 4, the laser emission optical system usually includes, as elements of the optical system, a mirror 12 for reflecting the laser light from the optical fiber 11 downward and a spread of the laser light from the mirror 12. Recollimating lens 13
And a focus lens (working lens) 14 for irradiating the laser light spot so as to be focused at a working point on the work. These elements are housed in a cylindrical casing (not shown).

[0004] Further, the laser emission optical system often includes an observation optical system for observing the irradiation area of the work with the laser light. The observation optical system is used for observing the processing state during processing and for performing teaching prior to processing. The observation optical system is often realized by the CCD camera 15, and is mounted on the upper part of the casing. When such an observation optical system is provided, the mirror 12
The one that reflects laser light and transmits visible light is used. Then, the mirror 12, the recollimating lens 1
3. The focus lens 14 and the CCD camera 15 are installed so as to be located on a straight line on the optical axis of the laser beam. In particular, the mirror 12 is provided so as to form an angle of 45 degrees with the optical axis.

[0005] In FIG. 4, the laser beam from the optical fiber 11 is directly introduced into the mirror 12.
There is a case where another reflection mirror is arranged on the incident side of 2, that is, on the side of the casing, and laser light incident from above through an optical fiber is incident on the mirror 12 by this reflection mirror.

In such a laser emission optical system, incident laser light is divided and irradiated onto a work, or irradiated by rotating a laser light spot on a work so as to draw a circular locus. Has been proposed. The proposal to split the incident laser light and irradiate it on the work is
For example, it is disclosed in Japanese Patent Application No. 11-86062, and a so-called roof-type prism having two inclined surfaces is used as an element for division. On the other hand, a proposal in which a laser beam spot is rotated so as to draw a circular trajectory on a workpiece and irradiated is disclosed in Japanese Patent Application No. 11-86068, for example, which has one inclined surface as an element for rotation. That is, a so-called tilted prism is used. Hereinafter, when it is called a prism, it includes both a roof type prism and an inclined prism.

In the case where a prism is incorporated in the laser emission optical system, a prism 20 (shape is shown as a roof type prism) and a mirror 12 and a recollimating lens 13 as shown in FIG. May be arranged at a position a, between the recollimating lens 13 and the focus lens 14, at a position b, or at a position c below the focus lens 14. In addition,
FIG. 5 shows a configuration in which another reflection mirror 16 is arranged on the incident side of the mirror 12 described in FIG. 4, that is, on the side of the casing.

[0008]

However, in these cases, the images observed by the CCD camera 15 become two when the roof-type prism is arranged, and when the prism is rotated or moved, the observation image becomes two. Moves with a change in the position of the prism. As a result, the machining position cannot be clearly observed, and accurate teaching cannot be performed.

To solve such a problem, FIG.
As shown in (2), it is conceivable to arrange the prism 20 not on the optical axis of the observation optical system but on the side of the casing.
In this case, the recollimating lens 13 also needs to be arranged on the side of the casing. However, when such a configuration is employed, the weight balance of the entire laser emission optical system is deteriorated. This becomes difficult to apply, for example, when the laser emission optical system is mounted on a robot arm and moved three-dimensionally.

It is an object of the present invention to provide a laser emission optical system that allows a processing point to be easily observed, reduces the size of the entire emission optical system, and improves performance and operability. It is in.

[0011]

According to the present invention, an optical system for irradiating a laser beam is incorporated in a casing. As an element of the optical system, an incident laser beam can be divided,
In a laser emission optical system including a prism for rotating the workpiece so as to draw a circular locus and a processing lens for irradiating the workpiece with laser light from the prism, the prism and the processing lens are the same. A first mirror that is disposed on an optical axis and that transmits laser light from the prism and reflects visible light from the work side on the optical axis between the prism and the processing lens; And an observation optical system for receiving the reflected light from the first mirror and observing an area including the work.

In the present laser emission optical system, an optical fiber for introducing a laser beam is coupled to the casing so as to be located on the optical axis, and the laser fiber from the optical fiber is incident on the prism. A prism is arranged.

In the laser emission optical system, a recollimating lens is further disposed between the prism and the processing lens, and the first mirror is provided between the recollimating lens and the processing lens. It is arranged at an angle of 45 degrees to the axis.

In the present laser emission optical system, since a part of the laser light is reflected by the first mirror, a cooling block is provided at a position where the laser light is reflected by the first mirror. I have.

In the laser emission optical system, the observation optical system further includes a second mirror for receiving the reflected light from the first mirror and reflecting the reflected light upward or downward, and the first mirror. And a CCD camera for receiving the reflected light from the mirror.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a laser emission optical system according to the present invention will be described with reference to FIG. The laser emission optical system according to the present embodiment is, similarly to the above-described conventional laser emission optical system, a light for introducing laser light from a laser oscillator as an element of an optical system for irradiating laser light to a work. Fiber 11, recollimating lens 1
3, including the focus lens 14. Here, a roof-type prism 20-1 for dividing incident laser light into two is provided as a prism. Of course, when rotating the laser spot light so as to draw a circular locus on the work, an inclined prism is disposed instead of the roof type prism 20-1.

In this embodiment, the roof prism 20-
1, the collimating lens 13 and the focus lens 14 are arranged on the same optical axis in a straight line. In addition, an optical fiber 11 for introducing a laser beam is coupled to an upper portion of a casing (not shown) via an emission supporting portion of the optical fiber 11 so as to be located on the optical axis, and a roof prism 20-
Numeral 1 is disposed immediately below the emission section of the optical fiber 11 so as to directly receive the laser beam from the optical fiber 11.

In this embodiment, the roof type prism 2
On the optical axis between 0-1 and the collimating lens 13, the first mirror 10 that transmits the laser beam from the roof prism 20-1 and reflects the visible light from the work side is arranged. . In particular, the first mirror 10 is arranged at an angle of 45 degrees with respect to the optical axis. An observation optical system for receiving the reflected light of the visible light from the first mirror 10 and observing a region including the workpiece is disposed on a side of the casing. The observation optical system includes a second mirror 21 for receiving reflected light of visible light from the first mirror 10 and reflecting the reflected light upward, and a CCD for receiving reflected light from the first mirror 21. And a camera 15. Of course, the reflected light of the visible light from the first mirror 10 may be reflected downward by the second mirror 21, or the reflected light of the visible light from the first mirror 10 may be reflected without the second mirror 21. The image may be directly received by the CCD camera 15.

It is difficult for the first mirror 10 to transmit 100% of the incident laser light, and several percent of the
Is reflected. When the reflected laser beam hits the casing, the casing is heated. With this in mind,
The cooling block 22 is provided at the position where the first mirror 10 reflects the laser light, that is, at the side of the casing. The cooling block 22 generally includes a block portion for receiving the reflected laser beam and cooling means for cooling the block portion by water cooling or the like.

With the above configuration, a clear observation image which is not affected by the roof prism 20-1 can be obtained in the observation optical system. In addition, while the second mirror 21 and the CCD camera 15 arranged on the side of the casing are lightweight, each element of the emission optical system is arranged substantially in a straight line on the optical axis of the laser light, so that the emission optical The weight balance of the entire system is improved, and the system can be easily applied to a system in which the emission optical system itself is moved, such as being mounted on a robot arm.

For example, a description will be given of a case where the present emission optical system is applied to a weaving optical system in which a laser beam spot is rotated on a work by rotating a tilt prism to perform bead welding with reference to FIGS. I do.

As shown in FIG. 2, the CCD camera 15
If the inclined prism 20-2 is on the optical axis of, the image field of view on the monitor for displaying the image obtained from the CCD camera 15 will rotate during teaching. Therefore, teaching is difficult unless the rotation of the inclined prism 20-2 is stopped. Further, even when the inclined prism 20-2 is stopped, it is difficult to specify the rotation center of the laser light spot on the monitor, and the rotation center of the laser light spot is located at a point or a line to be processed. Teaching is difficult.

When this emission optical system is applied, as shown in FIG. 3, even if the inclined prism is rotated, the image field on the monitor does not rotate. In addition, the center of rotation of the laser beam spot is once actually irradiated with the laser beam for one round onto the work,
The center of the bead can be specified by marking it on a monitor with a line generator or the like. This facilitates teaching the center of rotation of the laser beam spot to a point or line to be processed regardless of the rotation of the tilt prism.

In addition, the output support portion of the optical fiber 11 has a structure that maintains rigidity so that it can cope with fixing the weight of the optical fiber including the coating of the optical fiber and moving the output optical system. Is getting bigger. In particular,
In the case of a high-output YAG laser, it is necessary to cool the optical fiber emission part, and the weight and shape are further increased due to this cooling system. In this case, the emission support of the optical fiber 11 is
If it is off the axis of the nozzle at the lower end of the casing, the focus lens, and the recollimating lens, the moment of inertia of the entire output optical system will increase.When mounting the system on the system that moves the output optical system, consider the rigidity further. There must be.

On the other hand, in this emission optical system, the nozzle portion,
The focus lens, the collimator lens, and the optical fiber emission support portion can be arranged substantially uniaxially. Also,
The CCD camera 15 and the second mirror 21 are small in weight,
Even if it deviates from the axis, the influence on the moment of inertia is extremely small.

The embodiment of the present invention has been described above.
The laser emission optical system according to the present invention is applicable to any of a drilling device and a welding device. Therefore, the laser oscillator is not limited to the YAG laser oscillator, but may be any laser oscillator used for laser processing, for example, a YLF laser oscillator or a CO ₂ laser oscillator. Further, either a pulsed laser or a continuous laser may be used.

[0027]

According to the present invention, there is provided a laser emission optical system capable of easily observing a processing point, reducing the size of the entire emission optical system, and improving performance and operability. be able to.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a laser emission optical system according to the present invention.

FIG. 2 is a diagram for explaining a problem in a case where a conventional laser emission optical system includes an inclined lens.

FIG. 3 is a diagram for explaining teaching in a case where an inclined lens is provided in the laser emission optical system of the present invention.

FIG. 4 is a schematic configuration diagram showing a conventional general laser emission optical system.

FIG. 5 is a diagram for explaining an example of arrangement of a tilt lens when a tilt lens is provided in a conventional laser emission optical system.

FIG. 6 is a diagram for explaining another example of the arrangement of the tilt lens when the conventional laser emission optical system includes the tilt lens.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 1st mirror 11 Optical fiber 12 Mirror 13 Recollimating lens 14 Focus lens 15 CCD camera 16 Reflection mirror 20 Prism 20-1 Roof type prism 20-2 Inclined prism 21 Second mirror 22 Cooling block

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E068 CB05 CB06 CB09 CC02 CD03 CD09 CD12 CD15 CE08 5F072 AB01 HH02 JJ01 KK05 KK30 MM08 TT01 YY06

Claims (5)

[Claims] An optical system for irradiating a laser beam is built in a casing, and as an element of the optical system, an incident laser beam is split or rotated so as to draw a circular locus on a workpiece. In a laser emission optical system including a prism for causing the laser beam from the prism to irradiate the workpiece with a laser beam, the prism and the processing lens are arranged on the same optical axis. On the optical axis between the prism and the processing lens, a first mirror that transmits laser light from the prism and reflects visible light from the work side is disposed. A laser emission optical system comprising an observation optical system for receiving reflected light and observing a region including the work. 2. The laser emission optical system according to claim 1, wherein an optical fiber for introducing a laser beam is coupled to said casing so as to be located on said optical axis, and said laser beam from said optical fiber is transmitted through said optical fiber. A laser emission optical system, wherein the prism is arranged so as to be incident on the prism. 3. The laser emitting optical system according to claim 2, further comprising a recollimating lens disposed between said prism and said processing lens, wherein said first mirror is provided with said recollimating lens and said processing lens. A laser emission optical system, which is disposed at an angle of 45 degrees with respect to the optical axis. 4. The laser emission optical system according to claim 3, wherein a very small portion of the laser light is reflected by the first mirror, and is cooled to a position where the laser light is reflected by the first mirror. A laser emission optical system comprising a block. 5. The laser emission optical system according to claim 3, wherein the observation optical system receives a reflected light from the first mirror and reflects the reflected light upward or downward. A laser emission optical system, comprising: a mirror; and a CCD camera for receiving light reflected from the first mirror.