JPH0985470A - Laser beam marking device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam marking device which marks exactly by definitely controlling the working distance against a great variety of works with different thickness or height with a comparatively simple composition. SOLUTION: An optical system including turning mirrors 5, 7 and a light collecting means 9 is composed movable to the direction of approaching to the front face of a work or the direction of separating. A detecting means 17 detecting the interval between the light collecting means 9 and the front face of the work 10 is installed, responding to the detected result of this detecting means 17, the optical system is composed so as to be moved to the direction vertically with the front face of the work 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser marking device for performing marking processing on a work by scanning laser light generated from a laser oscillator in the XY2 directions and condensing it on the surface of the work.

[0002]

It has been more than 30 years since it was first shown that laser action could actually occur by using ruby crystals as a laser medium. Over time, the term laser has become routine, and not only that it is now an indispensable tool for a wide range of fields from industrial production to medicine, and in the conduct of many scientific measurements and studies. , Is the basis. Processing using a laser beam has been actively performed conventionally. For example, for laser welding, laser cutting, etc., CO ₂
It is performed using a laser or a YAG laser. For the fine processing of electronic devices and chemicals, processing with laser light such as excimer laser having a short wavelength is also actively performed.

Among them, recently, the PL law (Product Liability Law)
As a result of the enforcement of the regulations, it is necessary to display warnings on the products, display the manufacturer, etc., and to mark various products. Laser marking is mainly done by using YAG laser, which makes non-contact marking on products,
It is also a marking method which has many advantages such as high productivity by high-speed marking and no contamination of the surrounding environment.

The structure of a conventional laser marking device will be described below with reference to the drawings.

FIG. 4 is a diagram showing a configuration example of a conventional laser marking device. The laser beam emitted from the laser oscillator 51 has its optical axis changed from the X1 direction to the Y1 direction by the first mirror 52, and has its optical axis changed to the Z1 direction perpendicular to the Y1 direction by the second mirror 53. Then the second mirror 5
By changing the optical axis of the laser light from the laser beam 3 from the third mirror 54 in a direction parallel to the Y1 direction, and rotating the first rotating mirror 55 by the first rotating means 56. The laser light can be scanned in the Y and Y directions.
Further, the laser beam from the first rotating mirror 55 can be scanned in the X direction by rotating the second rotating mirror 57 by the second rotating means 58. The laser light from the second rotating mirror 57 is condensed by the condensing means 59, is focused on the work 60, and rotates the first rotating mirror 55 and the second rotating mirror 57. By doing so, laser light is irradiated to a predetermined position on the work 60 while scanning in the XY2 directions, and marking is performed.

[0006]

However, in such a configuration, when the distance (working distance) between the light converging means and the work surface cannot be made constant, for example, when the work thickness or height is different, a predetermined value is obtained. It is not possible to perform accurate marking with the beam diameter of.

Therefore, there is a method of raising and lowering the work itself to make the working distance constant, but a mechanism for raising and lowering the work due to the weight of the work becomes large, and it is difficult to cope with a wide variety of works and high productivity is achieved. It had a problem that it could not be obtained.

The present invention solves the above-mentioned problems of the prior art by controlling the working distance of a wide variety of works having different thicknesses or heights with a relatively simple structure. It is an object of the present invention to provide a laser marking device that can perform accurate marking.

[0009]

To achieve this object, a laser marking device of the present invention focuses a laser beam on a work surface by a focusing means and scans the work surface by a rotating mirror. In a laser marking device for marking, an optical system including a rotating mirror and a light converging means is configured to be movable in a direction closer to or away from a work surface, and a distance between the light converging means and the work surface is detected. A detecting means is provided, and the optical system is configured to move in a direction perpendicular to the surface of the work according to the detection result of the detecting means.

The present invention also includes a laser oscillator, and a first mirror for changing the optical axis of laser light emitted from the laser oscillator and traveling in a first direction in a second direction perpendicular to the first direction. A second mirror for changing the optical axis of the laser light traveling in the second direction to a third direction perpendicular to the first direction and the second direction, and laser light traveling in the third direction A third mirror that changes the optical axis in a direction parallel to the second direction; a first rotating mirror that scans the laser light from the third mirror in the second direction; First rotating means for rotating the first rotating mirror, a second rotating mirror for scanning the laser light from the first rotating mirror in the first direction, and the second rotating mirror. Second rotating means for rotating the moving mirror, and light collecting means for collecting the laser light from the second rotating mirror. The third mirror, the first, second
Holding mirror for fixing the turning mirror, the first and second turning means, and the light collecting means, guiding means for guiding the holding plate in parallel with the third direction, and the holding plate for the holding plate. Concretely, it is provided with a driving means for moving in parallel with the third direction, a supporting means for fixing the work perpendicularly to the third direction, and a detecting means for detecting a distance between the light collecting means and the work. It has a simple structure.

According to the present invention, when laser marking is performed on a wide variety of works having different thicknesses or heights, the works are moved up and down in order to keep the distance (working distance) between the focusing means and the work constant. Instead, by raising and lowering the focusing means and the rotating mirror, the working distance can be made constant, accurate marking can be performed, and a laser marking device with high productivity can be provided.

[0012]

DETAILED DESCRIPTION OF THE INVENTION A laser marking apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a laser marking apparatus according to an embodiment of the present invention, in which 1 is a laser oscillator, and 2 is a laser oscillator 1 which reflects incident light in the X1 direction in the Y1 direction. 1 is a first mirror that changes its optical axis in the XY plane, and 3 is a second mirror that reflects the incident light from the first mirror 2 in the Z1 direction perpendicular to the first XY plane. Four
51, 52, and 53, and the same configurations as those already described, and they are fixed at predetermined positions.

Reference numeral 4 denotes a third mirror arranged on a second XY plane parallel to the first XY plane, and the second mirror 3
Is a third mirror that reflects the laser light from the and changes its optical axis to a direction parallel to the Y1 direction in the second XY plane. Reference numeral 5 reflects the laser light received from the third mirror 4 to change the optical axis thereof in the −X1 direction and reciprocally rotate the optical axis of the reflected light in the XY plane about the −X1 direction.
First for scanning the laser light on the work 10 in the Y direction
Is a rotating mirror, and is connected to the first rotating means 6 including, for example, a stepping motor and the like with the same rotating shaft.

Reference numeral 7 is a second rotating mirror which is capable of reciprocating rotation about an axis in the Y direction, receives the laser light from the first rotating mirror 5, and sets its optical axis in the Z2 direction in the XZ plane. Is reciprocally rotated in a direction parallel to the X axis.
Reference numeral 8 is a second rotating means coupled to the second rotating mirror 7, and like the first rotating means 6, a stepping motor or the like is used. Reference numeral 9 denotes a condensing unit for converging the laser light from the second rotating mirror 7 onto the surface of the work 10.
For example, it is composed of a converging lens and the like. 30 is work 1
It is a supporting means for fixing 0.

In the above structure, the third mirror 4, the first rotating mirror 5, the first rotating means 6, the second rotating mirror 7, the second rotating means 8 and the light collecting means. 9 (these are referred to as optical system movable parts) are attached to a holding plate 11 movable in the vertical direction (Z direction) while maintaining a predetermined optical positional relationship to form a movable part of the optical system. There is. The first
The rotating mirror 5 and the first rotating means 6 are
If the length in the Z direction is set to be sufficiently large, it does not need to be movable in principle, but it is better to configure the above parts so that they can move up and down as a unit to improve the positional relationship between the optical elements. Can be kept accurate.

FIG. 2 shows in detail the moving mechanism of the movable parts 4-9 of the optical system. Reference numeral 11 denotes a holding plate that holds the above-mentioned movable optical system. Reference numeral 12 is a guide means for movably supporting the holding plate 11 in the vertical direction, and a pair of left and right guide means 12a, 12b.
(FIG. 1). The specific configuration of the guide means 12 is not particularly limited, but may be, for example, a fixed member and a movable member in which the other member slides in a groove provided in one member. Good. 14
Is a drive device for moving the holding plate 11 up and down, and is composed of, for example, a stepping motor. 1
Reference numeral 3 denotes a support plate fixed to a fixed portion of the apparatus, and the fixed member and the movable member of the guide means 12 are the support plate 1 respectively.
3, fixed to the holding plate 11. The control mechanism of the driving means 15 will be described later. Reference numeral 15 is a ball screw coupled to the driving means 14, and is arranged parallel to the Z direction. 16 is a nut screwed with the ball screw 15,
It is fixed to the holding plate 11.

In FIG. 1, reference numeral 17 denotes a detection means for detecting the height of the surface of the work 10 (position in the Z-axis direction-changing depending on the thickness or height of the work 10). Various methods such as a sound wave method can be used.

FIG. 3 is an example of a control system for moving the optical system movable parts 4 to 9 up and down according to the height of the surface of the work to keep the working distance constant.
The surface height data of the workpiece 10 detected by the amplifier 18
Is amplified by. The control device 19 compares the built-in working distance reference data with the surface height data detected by the detection means 17, and controls the drive power supply 20 based on the error signal to drive the drive means 14 forward or reverse. Then, the holding plate 11 is moved up and down through the transmission mechanisms 15 and 16 to control the working distance to a desired value. In some cases, instead of detecting the height of the surface of the work 10 by the detecting means 17, or in combination with this, the lot of the work 10 is transferred to the work supply device side for feeding the work 10 to the laser marking position. The average thickness or height of the data is held, and this data is input to the control device during the work feeding operation to the laser marking position, and based on this, the working distance is almost the desired value. As described above, the position of the movable part of the optical system in the Z direction may be controlled in advance before the surface height of the work is observed. If the rough adjustment is sufficient for the adjustment of the working distance, only the preliminary adjustment is necessary. However, when the fine adjustment is necessary, the control using the detection signal of the detecting means 17 is effective.

Next, the operation of the device of the present invention will be described. The laser light emitted from the laser oscillator 1 is reflected by the first mirror 2 in the same first XY plane as the emitted laser light,
The optical axis is changed from the X1 direction to the Y1 direction, and by the second mirror 3, Z which is perpendicular to the first XY plane and faces upward in the drawing.
The optical axis is changed in one direction.

Next, the laser beam from the second mirror 3 is directed by the third mirror 4 arranged on the second XY plane parallel to the first XY plane in the Y1 direction in the second XY plane. By changing the optical axis of the laser light in a direction parallel to and rotating the first rotating mirror 5 by the first rotating means 6,
Laser light can be scanned in the Y direction.

Further, the laser beam from the first rotating mirror 5 can be scanned in the X direction by rotating the second rotating mirror 7 by the second rotating means 8.

The laser light from the second rotating mirror 5 is condensed by the condensing means 9 and focused on the work 10,
By rotating the first rotating mirror 5 and the second rotating mirror 7, laser light is irradiated to a predetermined position on the work 10 to perform marking.

The third mirror 4, the first rotating mirror 5, the first rotating means 6, the second rotating mirror 7, the second rotating means 8 and the light collecting means 9 are holding plates. It is fixed at 11.
Further, the holding plate 11 includes a pair of guide means 12 and drive means 13
Thus, it is possible to move in the Z direction, and the moving distance or the distance (working distance) between the light collecting means 9 and the work 10 is detected by the detecting means 17.

According to the detection signal, the driving means 13 is moved to move the holding plate 11 up and down to make the working distance constant. Since the holding plate 11 moves in the Z direction, the second
Although the distance between the mirror 3 and the third mirror 4 changes, the optical axis of the laser light between them changes in the Z direction, and as a result, the laser optical axes in the optical system movable parts 4 to 9 do not change.

[0026]

According to the present invention, when marking a wide variety of works having different thicknesses or heights, the distance between the light collecting means and the work surface (working distance).
In order to maintain a constant
By moving the rotating mirror up and down to the optimum position, the working distance can be made constant, accurate marking can be performed, and a device with high productivity can be provided.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a laser marking device according to an embodiment of the present invention.

FIG. 2 is a specific example diagram of a vertical movement mechanism.

FIG. 3 is an exemplary configuration diagram of a control system of a vertical movement mechanism.

FIG. 4 is a perspective view of a conventional laser marking device.

[Explanation of symbols]

 1 Laser Oscillator 2 First Mirror 3 Second Mirror 4 Third Mirror 5 First Rotating Mirror 6 First Rotating Means 7 Second Rotating Mirror 8 Second Rotating Means 9 Condensing Means 10 Work 11 Holding Plate 17 Detecting Means 19 Control Device 30 Supporting Means

Claims (2)

[Claims] 1. A laser marking apparatus for concentrating a laser beam on a surface of a work by means of a converging means and scanning the surface of the work by means of a rotating mirror for marking, wherein an optical system including the rotating mirror and the converging means is provided. , Is configured to be movable in a direction closer to or away from the work surface, and is provided with detection means for detecting a distance between the light condensing means and the work surface, and the optical system of the work is determined according to the detection result of the detection means. A laser marking device characterized in that it is configured to move in a direction perpendicular to the surface. 2. A laser oscillator, a first mirror for changing an optical axis of laser light emitted from the laser oscillator and traveling in a first direction to a second direction perpendicular to the first direction, and the second mirror. A second mirror that changes the optical axis of the laser light that travels in the first direction to a third direction that is perpendicular to the first direction and the second direction, and a laser light that travels in the third direction. A third mirror that changes the optical axis in a direction parallel to the second direction; a first rotating mirror that scans the laser light from the third mirror in the second direction; and a first rotation mirror. A first rotating means for rotating the moving mirror; a second rotating mirror for scanning the laser light from the first rotating mirror in the first direction; and a second rotating mirror. Second rotating means for rotating, light collecting means for collecting the laser light from the second rotating mirror, and the third mirror. Rail, the first and second rotating mirrors, the first and second rotating means, and a holding plate for fixing the light collecting means, and the holding plate is guided in parallel with the third direction. Guide means, drive means for moving the holding plate in parallel with the third direction, support means for fixing the work in the third direction, and a distance between the light collecting means and the work is detected. A detection means is provided, Claim 1 characterized by the above-mentioned.
The laser marking device according to the above.