JPH05146887A - Marking control method for scanning type laser beam marker - Google Patents

Abstract

PURPOSE:To provide the marking control method of the scanning type laser beam marker which eliminates an adjusting mechanism improves vibration resistance and adjusts the orthogonality and parallelism in a short time. CONSTITUTION:In the marking control method of the scanning type laser beam marker to perform marking by a scanning system by using a first galvanometer and a second galvanometer, the first and second galvanometers are operated, respectively to measure angles alpha (radian) and beta formed between a marked straight line and an X axis which is a reference line of a positioning mechanism of a work and convert these into the position at an orthogonal coordinate system under a specified condition. The minute variations of a marking shape in the mobile axial direction of the first galvanometer and the second galvanometer are them calculated from an initial position coordinate value and a final position coordinate value of marking which are synchronized with a laser beam pulse. A coordinate value obtained by adding the calculated minute variations to the initial position coordinate value is given to the first galvanometer and the second galvanometer in order, the sequence of points produced by the laser beam pulse is overlapped and marking is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marking control method for a scanning type laser marker for marking with a scanning method using two galvanometers.

[0002]

2. Description of the Related Art In a scanning type laser marker for marking with a scanning method using two galvanometers, in the conventional marking control method, it depends on the orthogonality determined by the mounting positions of the two galvanometers and the angle formed by the galvanometer system and the workpiece positioning mechanism. The following adjustments were made in order to obtain the determined parallelism accurately.

(1) Adjustment of orthogonality:

.. The two galvanometers are moved independently to mark two straight lines passing through the origin.

.. The angle at which these two straight lines intersect at the origin is measured.

[0006] The gimbal mechanism repeatedly adjusts the relative angular relationship between the two galvanometers by trial and error so that the angle at which the two straight lines intersect becomes π / 2.

(2) Adjustment of parallelism:

One of the above two straight lines is utilized by using a clearance hole in a portion where the base fixing the galvanometer system is attached or a mechanism for sliding the base fixing the galvanometer system in the θ direction. The mounting angle of the base is adjusted by trial and error so that the angle formed by the direction of the reference line at which the workpiece is positioned is 0 (radian).

[0009]

However, in the above-mentioned conventional example, adjustment of the orthogonality and parallelism determined by the mounting position of the galvanometer system is performed by trial and error.
Furthermore, since a gimbal mechanism or the like for adjusting the orthogonality is required, there is a disadvantage that it is weak against vibration and takes a long time to adjust.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to improve the disadvantages of the prior art, especially to improve the vibration resistance by eliminating the adjusting mechanism and to adjust the orthogonality and parallelism in a short time. Provided is a marking control method for a laser marker.

[0011]

Therefore, in the present invention, in the marking control method of the scanning type laser marker in which the first galvanometer and the second galvanometer are used to perform marking by the scanning method, the first galvanometer is operated independently. Then, a straight line of a fixed length is marked, and the angle α (radian) formed by the x-axis, which is the reference line of the positioning mechanism of the workpiece on which this straight line is marked, is measured, and the second galvanometer is operated independently to fix the fixed length. The straight line is marked and the angle β (radian) with the x axis that is the reference line of the workpiece positioning mechanism on which this straight line is marked is measured, and the origin of the orthogonal coordinate system when α ≠ 0 or β ≠ π / 2 And α = 0 and β = π / 2, the origins of the Cartesian coordinate system are made to coincide, and α ≠ 0 or β ≠ π / 2
The position on the Cartesian coordinate system when is α =
Converting to a position in the Cartesian coordinate system when 0 and β = π / 2, and marking in the moving axis direction of the first galvanometer and the second galvanometer from the initial position coordinate value and the final position coordinate value of the marking. The minute change amount of the shape is calculated, and the coordinate value obtained by adding the calculated minute change amount to the initial position coordinate value is sequentially given to the first galvanometer and the second galvanometer in synchronization with the laser pulse at every constant minute time. , The markings are made by overlapping the point trains produced by the laser pulses one after another. This aims to achieve the above-mentioned object.

[0012]

[Operation] First, each galvanometer is independently marked with a straight line by a fixed length, and the angle between the x-axis, which is the reference line of the positioning mechanism of the workpiece on which each of these two straight lines is marked, that is, α and β (radian) are measured. To do. α = 0, β =
When π / 2, the galvanometer and the workpiece positioning mechanism have a high degree of parallelism, and since the two galvanometers are orthogonal to each other, there is no need for coordinate conversion and marking of a pattern results in the specified angle. And an exact pattern with length is obtained. However, when α ≠ 0 or β ≠ π / 2, the Cartesian coordinate system in this case is Ω,
The orthogonal coordinate system determined when α = 0 and β = π / 2 is set to Ω0, and the origins of these two coordinate systems Ω0 and Ω are made to coincide, and the position (x, y) in the coordinate system Ω0 is calculated by the following equation. It is converted to the position (X, Y) in the coordinate system Ω by using.

X = (xsinβ-ycosβ) / sin (β-α)

Y = (− xsin α + ycos α) / sin (β−α)

In the case of marking next, a value in which X and Y are increased by small amounts ΔX and ΔY from the initial position at regular time intervals Δt is synchronized with the laser pulse and sequentially X-valued.
By giving to the galvanometers of the axis and the Y axis, the point trains produced by the laser pulses are overlapped one after another to be processed, and finally the target position is reached.

Here, when marking a straight line having an angle φ with the x-axis at the speed v, ΔX and ΔY are obtained by the following equations.

ΔX = vsin (β−φ) / sin (β−α) Δt

ΔY = vsin (α−φ) / sin (β−α) Δt

An arc centered on the origin (radius r, θs
≦ θ ≦ θe) When marking an arc, it is calculated by the following formula.

ΔX = −vcos (nv / rΔt + θs−β) / sin (β−α) Δt

ΔY = vcos (nv / rΔt + θs−α) / sin (β−α) Δt

Here, n is the number of times of increase and takes a value of 1≤n≤N. However, N is the number of increases when θ coincides with θe.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

The optical part of the laser marker is composed of two fixed galvanometers, a beam expander, a reflection mirror, an fθ lens, two galvanometers and software for controlling the laser and correcting the designated movement amount. ing.

Next, the operation of this embodiment will be described.

Here, the lines drawn when the two galvanometers are moved independently for marking are two straight lines that intersect at the origin, and are drawn at the designated position with the designated length. It is assumed that the system gain (the ratio of the actual marking length to the specified length) has been correctly adjusted.

The machine coordinate system on the marking plane determined by the mounting angles of the two galvanometers is defined as (x, y), which is the orthogonal coordinate system as the work coordinate whose x axis is the direction of the reference line on which the work to be marked is positioned. Of 2
The two axes are the X axis and the Y axis, and the angles formed by the X axis and the Y axis with the x axis are α and β (radians), respectively.

The two galvanometers are mechanically fixed to the holder.

.. First, each galvanometer is independently marked with a straight line by a fixed length p (mm), and the angle between α and β (radian) with respect to the x axis that is the reference line of the workpiece positioning mechanism on which these two straight lines are marked measure. Here, it is assumed that the precision of the mechanism assembly regarding the parallelism and the orthogonality is within a range that requires further fine adjustment. That is, it is assumed that α = 0 and β = π / 2.

.. Coordinate conversion is performed based on the measured values of α and β. This is divided into the following (a) and (b).

(A) When α = 0 and β = π / 2: At this time, since the parallelism between the galvanometer and the workpiece positioning mechanism is high and the two galvanometers are orthogonal to each other, the coordinates are Marking a pattern without the need for conversion gives the exact pattern with the specified angle and length.

As shown in FIG. 2, when the two galvanometers are moved independently to perform marking, the drawn lines are orthogonal and parallel to the workpiece positioning mechanism, and when the system gain is correct, The rectangle and circle are drawn correctly when the rectangle and circle are specified.

(B). General cases other than (a) above:
As shown in Fig. 3, when the two galvanometers are moved independently for marking and the drawn lines are not orthogonal or parallel to the work positioning mechanism, the rectangle is parallel to four sides when a rectangle and a circle are specified. As a shape,
Also, the circle is drawn as an ellipse.

The orthogonal coordinate system in this case is Ω, and α = 0,
An orthogonal coordinate system determined when β = π / 2, that is, the work coordinate in (a) above is set to Ω0. Here, the origins of these two coordinate systems Ω0 and Ω are made to coincide.

As shown in FIG. 4, when the point (x, y) in the coordinate system Ω0 and the point (X, Y) in the coordinate system Ω represent the same point, the relationship is the coordinate system Ω0. Let (i, j) be the basic vector and (k, l) be the basic vector in the coordinate system Ω.

Xi + yi = Xk + Yl

K = cos αi + sin αj

L = cos βi + sin βj

From these relationships, it is known that the relationship between (x, y) and (X, Y) is generally expressed by the following equations (1A) and (1B).

X = Xcos α / a + Ycos β / b (1A)

Y = Xsinα / a + Ysinβ / b (1B)

Here, a and b respectively represent the ratio of the actual marking length to the designated length in the X-axis and Y-axis directions, that is, the system gain. Then, assuming that the values of a and b are adjusted to be 1, the equations (1A) and (1B) become the following equations (2A) and (2B).

X = Xcosα + Ycosβ (2A)

Y = Xsinα + Ysinβ (2B)

From the expressions (2A) and (2B), X and Y
Then, the following equations (3A) and (3B) are obtained.

X = (xsinβ-ycosβ) / sin (β-α) (3A)

Y = (− xsinα + ycosα) / sin (β−α) (3B)

As shown in FIG. 1, the position P (x, y) in the coordinate system Ω with no orthogonality or parallelism.
Is different from the designated position Q when viewed from the reference Cartesian coordinate system Ω0. Here, OA = OC = x, OB = OD = y
Is. At this time, the value (X, X) obtained by coordinate conversion using equations (3A) and (3B) so that the point Q is specified by the coordinate system Ω.
If Y) is indicated by the coordinate system Ω, the specified pattern to be originally drawn can be marked.

.. Mark it. This is divided into (a), (b) and (c) shown below.

(A) When marking a straight line: (X
A straight line connecting (s, Ys) and (Xe, Ye) is marked. From the (Xs, Ys) position, a value increased by small amounts ΔX and ΔY for both X and Y at constant time intervals Δt are sequentially given to the X-axis and Y-axis galvanometers in synchronism with the laser pulse, respectively. The point trains successively brought by the laser pulses are overlapped on top of each other to be processed, and finally the target position (Xe, Ye) is reached. If the coordinate system Ω0 and the coordinate system Ω are different, formulas (3A) and (3B)
As is clear from the above, ΔX and ΔY represented by the following equations (4A) and (4B) are designated.

ΔX = (Δxsin β−Δycos β) / sin (β−α) (4A)

ΔY = (− Δxsinα + Δycosα) / sin (β−α) ·· (4B)

When the straight line to be marked here forms an angle φ with the x-axis which is the reference line of the workpiece positioning mechanism,
If the speed of marking this straight line is v, Δx, Δ
y is given by the following equations (5A) and (5B).

Δx = vcosφΔt (5A)

Δy = vsinφΔt (5B)

Therefore, ΔX and ΔY can be expressed by the following equations (6A) and (6B) by the equations (4A) and (4B) and the equations (5A) and (5B).

ΔX = vsin (β−φ) / sin (β−α) Δt (6A)

ΔY = vsin (α−φ) / sin (β−α) Δt ... (6B)

(B). When marking an arc: Coordinates of points on a circle (radius r, θs ≤ θ ≤ θe) centered on the origins of two coordinate systems Ω0 and Ω with their origins coincident, in the coordinate systems Ω0 and Ω The values are (x, y), (X,
Y) can be expressed as the following equations (7A) and (7B).

X = rcos θ (7A)

Y = r sin θ (7B)

Therefore, Δx and Δy are expressed by the following equations (8A) and (8B).
Given in.

Δx = -rsin θ Δθ (8A)

Δy = rcos θΔθ (8B)

Here, when the linear velocity for marking an arc is v, the change amount Δθ of the angle θ for each time Δt is expressed by the following equation.

Δθ = v / rΔt (9)

The number of increases is n (1 ≦ n ≦ N, where N is θ
The angle θ when the number of increases is equal to θe) is expressed as follows by using the equation (9).

Θ = ΣΔθ = v / rΣΔt = nv / rΔt (10)

Therefore, the amounts ΔX and ΔY for increasing the X and Y coordinate values for each Δt are calculated by the following equations (11A) and (11B) from equations (3), (8), (9) and (10). ) Can be expressed as.

ΔX = -vcos (nv / rΔt + θs-
β) / sin (β-α) Δt ... (11A)

ΔY = vcos (nv / rΔt + θs−
α) / sin (β-α) Δt ... (11B)

(C). When marking an arbitrary pattern consisting of a straight line and an arc: only ΔX and ΔY shown in equations (6A) and (6B) and equations (11A) and (11B), respectively,
By increasing the position coordinate value of the galvanometer for each Δt, it is possible to mark the pattern having the specified shape.

This indicates that the specified pattern can be marked even if the normal fine adjustment is not made to α = 0 and β = π / 2.

[0074]

Since the present invention is constructed and functions as described above, according to the present invention, a gimbal mechanism for adjusting the mounting angle of the galvanometer and a mechanism for sliding the base fixing the galvanometer holder are not required, so that the vibration is eliminated. It is possible to strongly fix to the above, and when two galvanometers are independently moved to mark two straight lines passing through the origin, it is only necessary to measure the angle between each of the two straight lines and the reference direction of the work coordinates. To provide a marking control method for an excellent scanning-type laser marker that can be marked in a short time because marking can be performed as if it had been adjusted as if it had the orthogonality of the galvanometer system and the parallelism between the workpiece positioning mechanism. You can

[Brief description of drawings]

FIG. 1 is an explanatory diagram of coordinate conversion according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a case where two galvanometers are moved independently to perform marking in one embodiment of the present invention, the straight lines drawn are orthogonal to each other, and the parallelism with the work positioning mechanism is obtained; It is explanatory drawing of a coordinate system.

FIG. 3 is an explanation of the coordinate system when the two galvanometers are moved independently for marking in one embodiment of the present invention and the straight lines drawn are not orthogonal to each other, or the parallelism with the workpiece positioning mechanism is not obtained. It is a figure.

FIG. 4 is an explanatory diagram of affine transformation in the present invention.

[Explanation of symbols]

α Angle between straight line marked with first galvanometer and X axis β Angle between straight line marked with second galvanometer and X axis

Claims (2)

[Claims] 1. A marking control system for a scanning type laser marker, wherein marking is performed by a scanning method using a first galvanometer and a second galvanometer, and a straight line of a fixed length is marked by operating the first galvanometer independently. The angle α (radian) formed by the x-axis, which is the reference line of the workpiece positioning mechanism on which this straight line is marked, is measured, and the second galvanometer is operated independently to mark a straight line of a fixed length. The angle β (radian) formed by the x-axis, which is the reference line of the positioning mechanism of the workpiece to be marked, is measured, and the origin of the orthogonal coordinate system when α ≠ 0 or β ≠ π / 2 and α = 0 and β
The origin of the Cartesian coordinate system when = π / 2 is matched,
Scanning type characterized by converting a position in the orthogonal coordinate system when α ≠ 0 or β ≠ π / 2 into a position in the orthogonal coordinate system when α = 0 and β = π / 2 by affine transformation Laser marker marking control method. 2. A minute change amount of the marking shape in the moving axis direction of the first galvanometer and the second galvanometer is calculated from the initial position coordinate value and the final position coordinate value of the marking, and the minute change amount is calculated at every constant minute time. In synchronization with the laser pulse, coordinate values obtained by adding the calculated minute change amount to the initial position coordinate value are sequentially given to the first galvanometer and the second galvanometer, and the point trains caused by the laser pulses are overlapped one after another. The marking control method for a scanning type laser marker according to claim 1, wherein the marking is performed.