JPH06269971A - Laser beam machine - Google Patents

Abstract

PURPOSE:To enable high speed working with a wide range by providing a movable indicate means mounting a laser head equipped with a galvanoscanner, a ftheta lens and a laser beam source on a laser beam machine. CONSTITUTION:A laser head 1 equipped with a galvanoscanner 8 and a ftheta lens 7 and a movable indicate means mounting a laser beam source for supplying laser light to this laser head 1 and a laser head 1, are provided on a laser beam machine. Thus, since a gap between the laser beam source and a surface to be worked can be minimized and and kept constant, high speed working is possible over a very wide range. A laser spot diameter on a surface to be worked is stable, and the working reliability of the device can be improved. Also, by this constitution, since the number of the mirrors for a laser beam transmission can be reduced, and the number of the parts of an optical system for which high accuracy for assembling is required, can be reduced, working reliability is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus for marking characters such as characters on a surface of a steel plate or the like.

[0002]

2. Description of the Related Art As an example of a technique for marking a surface of an object such as a steel plate with a laser beam, a laser head equipped with an objective lens is movably supported along a surface to be processed, and a laser light source is provided. A laser marking device for irradiating the surface to be processed with a laser beam from the laser beam through an objective lens of a laser head to perform continuous marking is disclosed in, for example, Japanese Patent Laid-Open No. 57-14278.
No. 5 is disclosed.

In such a laser processing apparatus, since the laser head itself is mechanically driven for scanning, it is possible to scan the laser head over a wide range, but minute characters such as characters are scanned. There is a problem that scanning cannot be performed at high speed.

Further, since the laser light source is fixed to the outside and the laser light from the laser light source is transmitted toward the objective lens of the laser head by the mirror system, from the laser light source to the work surface depending on the laser irradiation position. The laser spot diameter on the surface to be machined is not constant due to changes in the divergence angle of the laser light, expansion of the beam diameter, etc. even if a collimating lens is used, resulting in a change in the machining shape or marking. There was the problem of becoming unclear.

On the other hand, a laser head having a galvano scanner for scanning the laser light from the laser light source in a desired direction and an fθ lens for condensing the laser light from the galvano scanner on a predetermined same plane is engraved. There is a laser marking device (see, for example, Japanese Patent Application Laid-Open No. 60-106686) that is movable along the surface to be processed and that performs continuous marking.

According to this apparatus, first, the laser head is moved to the marking start position and fixed at that position, marking is performed within a scannable range by the galvano scanner, and then the laser head is moved by a predetermined distance. The position is fixed at that position, and the marking is performed while scanning again with the galvano scanner, and the processing speed can be significantly improved compared to the case where the marking is performed while driving the entire laser head. However, since the galvano scanner requires high-speed response, the scanning mirror cannot be increased in size according to the beam diameter, and in the system in which laser light is transmitted to the laser head by the mirror system, the transmission distance cannot be expanded. However, the energy loss due to the beam expansion is increased, which causes a further serious problem, and it is difficult to apply to an apparatus that requires processing over a wide range such as a thick plate having a required processing range of several meters.

[0007]

SUMMARY OF THE INVENTION The present invention has been devised to solve the above-mentioned disadvantages of the prior art.
Its main purpose is to provide an improved laser processing device that can perform processing such as engraving on a wide range of surfaces at high speed without changing the machining shape or blurring the engraving. To provide.

[0008]

According to the present invention, there is provided a laser light source, a galvano scanner for scanning the laser light from the laser light source in a desired direction, and a laser from the galvano scanner. A laser head having an fθ lens for condensing light on a predetermined same plane, the laser light source and the laser head are mounted,
And it is achieved by providing the laser processing apparatus characterized by comprising movable support means movable along the surface to be processed of the workpiece.

[0009]

According to this structure, the distance between the laser light source and the surface to be processed can be kept constant at a minimum and the laser beam can be scanned by the galvano scanner, so that a wide range of markings can be performed at high speed. Further, since the number of mirrors for laser light transmission can be reduced, it is possible to reduce the transmission efficiency due to the mirrors and the processing defects due to the optical axis shift.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below with reference to specific embodiments shown in the accompanying drawings.

FIG. 1 is a partial cross-sectional side view showing the construction of a laser processing apparatus constructed according to the present invention. This device is for imprinting characters or the like on the surface of a steel plate P as a workpiece.

Guide means 2 is provided in the width direction (X direction) of the steel plate P.
A laser head 1 is mounted on a movable table 3 as a movable supporting means that is movably supported by. A laser oscillator 6 as a laser light source for supplying laser light to the laser head 1 is also mounted on the movable table 3. The movable table 3 is driven by a motor 4.

An fθ lens 7 is provided at a position facing the steel plate P in the laser head 1. A laser beam is supplied from the laser oscillator 6 to the fθ lens 7 via a galvano scanner 8 having galvano mirrors 8a and 8b and mirrors 9 and 10. here,
The fθ lens 7 is a lens whose focal position moves on one plane orthogonal to the optical axis depending on the incident angle. That is, the focus position of the laser emitted from the fθ lens 7 moves on the surface of the steel plate P within a predetermined range due to the change of the incident angle by the galvano scanner 8. A control unit 12 is provided at an appropriate position of the laser processing device, and the motor 4
The galvano scanner 8 is driven and controlled.

The operating procedure of this embodiment will be described below. A marking area 13 is preset on the steel plate P, and for example, 20 characters are laser-marked on the marking area 13. Here, the engraved area 13 is composed of, for example, four areas (A, B, C, D) defined by the scannable range of the galvano scanner 8 (or the size of the fθ lens 7).

First, the steel plate P is conveyed to and placed on the stage S, and the motor 4 is used to move the movable table 3 and the f.theta.
The center of the mark is the marking start position of the marking area 13 (center of area A)
Move to the position. Then, the space between the fθ lens 7 and the steel plate P is adjusted by an adjusting means (not shown), and the galvano scanner 8 is actually scanned to mark the area A.

Next, the movable table 3 is held with the motor 4.
Is moved to a position where the center of the fθ lens 7 becomes the center of the area B, the galvano scanner 8 is scanned, and the area B is marked. Similarly, marking is also performed on the areas C and D.

[0018]

As described above, according to the present invention, a laser head having a galvano scanner and an fθ lens, and a laser light source for supplying laser light to the laser head,
By providing the movable supporting means for mounting the laser light source and the laser head, the distance between the laser light source and the surface to be processed can be kept at a minimum and always constant. The diameter of the upper laser spot is stable, that is, the processed shape is stable, and the processing reliability of the device can be significantly improved. Further, with this configuration, it is possible to reduce the number of mirrors for laser light transmission, and it is possible to improve the processing reliability of the apparatus in that the number of parts of the optical system that requires high assembly accuracy can be reduced. it can.

[Brief description of drawings]

FIG. 1 is a schematic partial cross-sectional side view of a laser processing apparatus to which the present invention has been applied.

FIG. 2 is a view taken along the line II-II of FIG.

[Explanation of symbols]

 1 Laser Head 2 Guide Means 3 Movable Table 4 Motor 6 Laser Oscillator 7 fθ Lens 8 Galvano Scanner 8a, 8b Galvano Mirror 9, 10 Mirror 12 Control Unit 13 Marking Area P Steel Plate S Stage A, B, C, D Area

Claims (1)

[Claims] 1. A laser having a laser light source, a galvano scanner for scanning the laser light from the laser light source in a desired direction, and an fθ lens for condensing the laser light from the galvano scanner on a predetermined same plane. A laser processing apparatus comprising: a head; and a movable supporting means that mounts the laser light source and the laser head and is movable along a surface of a workpiece to be processed.