JPS60159714A - Laser automatic alignment device - Google Patents

Abstract

PURPOSE:To align an optical axis momently without deviation of a beam from the visual field by determining driving quantities of two mirror gimbals on a basis of outputs of two beam position detectors in accordance with prescribed operation formulas. CONSTITUTION:Since 4-quadrature detectors or charge coupled devices are used as beam position detectors 7 and 8 and a linearity can be given to relations between beam displacement and outputs of detectors, angular variations theta1 and theta2 of mirror gimbals 3 and 4 are determined unequivocally by operations based on output variations X1 and X2 of detectors 7 and 8. These operations are performed by an arithmetic unit 10 including a microprocessor, etc. As the result, the optical axis is aligned momently without deviation of the beam from the visual field.

Description

[Detailed description of the invention] (Technical field) The present invention relates to a laser automatic alignment device.

(Prior art) When a beam of light from a laser source or the like is passed through an optical path consisting of an arbitrary minute in space, generally the light af from the light source to the optical path is
A mirror is used as a means of f-transmission. In order to adjust the light so that it always passes through the tail region of the optical path despite spatial variations in the position of the light source and the light output angle (hereinafter referred to as alignment), there is a A necessary condition is to have at least two so-called mirror gimbals, in which mirrors are mounted on gimbals with axial degrees of freedom.

Traditionally, when alignment is performed visually.

As shown in FIG. 1, while repeating the operation of guiding the beam 2 from the laser light source 1 to the optical path input end 5 using the first gimbal 3 and guiding the beam 2 to the output end 6 using the second gimbal 4, , a method has been adopted in which the beam is aligned with the target optical path.

If this is to be automated, as shown in FIG. This becomes possible by converting it into a motor drive and providing means for forming a feedback loop from the fixed beam position detector 7 to the mirror gimbal 3 via the beam splitter 9, and from the beam position detector '8 to the mirror gimbal 4. .

In this conventional automatic alignment control device, only one mirror gimbal corresponds to one detection device as described above. That is, the two pairs of detection-drive systems operated independently. For this reason, when starting alignment from a state where the beam is misaligned with respect to the reference optical path, generally the first mirror gimbal 3 aligns the beam position with the optical path input end 5, and then the second mirror gimbal 4 adjusts the optical path. When the beam position is aligned with the output end 6, the beam position at the optical path input end 5 shifts, and it takes a considerable amount of time until the beam positions match at both input and output ends 5.6, that is, until the beam converges on the reference optical path. was there.

In the worst case, when the second mirror gimbal 4 aligns the vinyl position with the optical path output end 6, and the first mirror gimbal 3 aligns the beam position If with the optical path input end 5, the optical path output end 6
There was also a fear that the beam would be out of sight.

(Object of the Invention) An object of the present invention is to improve the above-mentioned drawbacks and provide a laser automatic alignment device in which there is no fear that the beam will deviate from the field of view.

(Structure of the Invention) The present invention includes two motor drive mirror gimbals for injecting a laser beam into a predetermined optical path, two beam position detection devices for measuring the beam position on this optical path, From the output of the beam position detection device, a laser automatic alignment device equipped with a paralysis device and a metal plate determines a predetermined feedback output for fully driving the mirror gimbal from the output of the two beam position detection devices. The automatic laser alignment apparatus is characterized in that it is provided with means for determining the drive amount of each of the mirror gimbals by a predetermined arithmetic expression.

(Example) Next, the present invention will be described in detail with reference to the drawings.

FIG. 3 is a perspective view showing a laser movement alignment device according to an embodiment of the present invention.

The main differences between this figure and Figure 2 are as follows.

An arithmetic unit 1° is provided to perform the following arithmetic operations. The entire explanation for deriving this calculation -ia'(i-) is given below.

Beam position detection device for alignment automation7.
When using a four-quadrant detector or a charge-coupled device (CCD), linearity can be guaranteed in the relationship between beam displacement and detector output. In this case problem t - To simplify, -
Focusing only on the axis, the output change X11 of the input end beam position detection device 7 with respect to the angle change θ1 of the first mirror gimbal 3. And the output change X21 of the output end beam position detection device 8 is modeled as follows.

X11=1θ1...(1)X21=KII
θl (2) Similarly, the output change X12 of the input end beam position detection device 7 with respect to the angle change θ2 of the second mirror gimbal 40. and the output change X22 of the output end beam vertical detection device 8 have the following relationship.

3θ2 to X11 = (3) 4θ to Xz2=
2 (4) Here, Kl to 4 are constants determined by the characteristics of the detection system, optical system, and drive coefficient. These (1).

From the relationships in equations (2), (3), and 14, the output changes Xi, X2 of each beam detection device 7°8 are equal to the angular changes θ1.4 of each mirror gimbal 3°4. It can appear as a linear combination of θ2.

Namely.

X1=X11+X12=113 t-)-Ka Ox
−・−・−(5)X2=X2x+X2z=Kxθ1+
to 4θ2...(6) These are the angle changes θ1. θ
If you solve the 2nd order, you will get the 1st order.

The above calculation is performed based on the output changes Xl, Xz of each beam position detection device 7.8, and the angle change θ1 . θ2t--can be arbitrarily determined. this(
If the calculation of equation (8) is applied to two axes using a calculation device 10 including a microprocessor or the like.

In an automatic beam alignment device, it is possible to instantaneously align the optical axis without the beam deviating from the field of view.

(Effects of the Invention) As described above, according to the present invention, the outputs of the two beam position detection devices that detect the entire beam position on the optical path to be aligned can effectively drive the two motor drives and mirror gimbals. Since the beam can be centered, there is no fear that the beam will go out of sight.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a conventional laser alignment machine based on visual observation of a laser beam, Fig. 2 is a perspective view showing the structure of a conventional laser automatic alignment device, and Fig. 3 is a perspective view of a conventional laser automatic alignment device according to an embodiment of the present invention. FIG. In the figure, 1... Laser light source, 2... Laser beam path, 3... First mirror gimbal, 4...
... Second mirror gimbal, 5 ... Alignment optical path input end %6 ... Alignment optical path output end, 7 ... Optical path input end beam position detection device,
8... Optical path output end beam position detection device, 9...
. . . Beam smitter for optical path input end beam position detection device, 10 . . . Arithmetic device.

Claims (1)

[Claims] Two ninth motor drive gimbals that direct the laser beam onto a predetermined optical path, two precise beam position detection devices that measure the beam position on the optical path, and the beam position detection device. and an arithmetic unit that determines a precise feedback output for driving the mirror gimbal based on the output. In the automatic laser alignment device, the driving amount of each of the two mirror gimbals is determined from the output of the beam position detection device 2115 to a predetermined value. What is claimed is: 1. A laser automatic alignment device, characterized in that it has a means for making a determination based on an arithmetic expression.