JPS6262226A - Laser alignment measuring apparatus - Google Patents

Abstract

PURPOSE:To obtain a small and accurate laser alignment measuring apparatus, by receiving and displaying a short-range view image and a long-range view image with the same image sensor and an image receiver. CONSTITUTION:An objective lens 11 and an eyepiece lens 12 form a Keplerian image transfer optical system. An image sensor 13 is arranged at a multi-reflection focusing position of the eyepiece lens 12 to receive a short-range view image 15 and a long- range view image 16 simultaneously to be displayed on an image receiver 14 simultaneously. When the position and the direction of travelling of a laser light is aligned accurately with a reference position (C), the centers of the image 16 and the image 15 coincide with a position (C). But when the position and the ongoing direction of the laser light is deviated or inclined, the center of the image 15 and the image 16 deviate from the position (C). The incident plane curvature, thickness, refractive index and focal range of an eyepiece lens are used to calculate a multi-reflection focusing point position f2' and a corresponding object point is calculated with the resulting position as image position of the short-range view image 15 to measure the short-range view image 15 and the long-range view image 16 simultaneously. With such an arrangement, an alignment measuring apparatus can be obtained which can measure the position and ongoing direction of the laser light accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser alignment measurement device that receives and displays a near-field image and a far-field image using a single image sensor and image receptor.

[Conventional technology]

In recent years, high-power laser systems configured with multistage amplifiers have come to be widely used in various industrial fields. In such a high power laser system,
In order to maintain high quality of output laser light or ensure stable operation of a system, an alignment measuring device that accurately measures the position and traveling direction of laser light is essential.

Conventionally, as this type of alignment measuring device, one having a configuration as shown in FIG. 4 has been used.

That is, a Keplerian image transfer optical system formed by an objective lens 41 and an eyepiece lens 421C, an image sensor 43 that forms a near-field image, and an image receptor 44 that displays it.
, an image sensor 46 that forms a far-field image, which is placed at the focal point of the light reflected by the beam splitter 450, and an image receiver 47 that displays the entire image.

The position of the laser beam is determined by measuring the amount of displacement of the near-field image 48 displayed on the image receptor 44 from the reference position according to the position on the image receptor screen. Further, the traveling direction of the laser beam is determined by measuring the inclination angle of the laser beam from the reference optical axis based on the position of the friend field image 49 displayed on the image receptor 47 on the image receptor screen.

[Problem that the invention seeks to solve]

The conventional laser alignment measuring device described above requires two sets of image pickup elements and image receptors because the near-field image and the far-field image are split into separate optical paths by a beam splitter. For this reason, there have been problems in that the device becomes large and expensive.

The present invention has been made in view of the above-mentioned problems, and uses the same image sensor and image receptor to receive near-field images and far-field images.
It is an object of the present invention to provide a second measurement device that enables the device to be miniaturized by displaying the following information.

[Means for solving problems]

In order to achieve the above object, the laser alignment measuring device of the present invention forms a Keplerian image transfer optical system with an objective lens and an eyepiece, and a near-field image and a far-field image are formed at the multiple reflection condensing position of the eyepiece. This configuration includes an image sensor that simultaneously receives images, and an image receiver that simultaneously displays a near-field image and a far-field image received by the image sensor.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

Figure 1 shows 10 parts of the laser alignment measuring device of this embodiment.
This is a diagram. In this embodiment, an objective lens 11 and an eyepiece lens 12 form a Kevlar type image transfer optical system. A plano-convex lens is used for the eyepiece/lens 12. The image sensor 3 is disposed at the multiple reflection condensing position of the eyepiece 12 so that it can simultaneously receive a near-field image and a far-field image. Further, the image receiver 4 is connected so as to simultaneously display a near-field image and a far-field image received by the image sensor I3.

In FIG. 1, the optical path indicated by a solid line is for a near-field image, and the optical path indicated by a chain line is for a far-field image. tfC,
In the screen of the image receptor 14, 15 is a near-field image, and 16 is a far-field image.

FIG. 2 is an enlarged view showing the multiple reflection optical paths of the eyepiece lens 12. In FIG. 2, the solid line optical path corresponds to a near-field image and exits in parallel from the exit surface of the eyepiece 12. Also,
A chain line optical path indicates a multiple reflection optical path that is reflected at the exit surface of the eyepiece lens 12 among the solid line optical paths, and a far-field image is transmitted to the image sensor 1.
3.

Figures 3 (a) to 3) show an example of measurement by the laser alignment measuring device of this embodiment, and show the displacement and inclination of the laser beam from the reference position in correspondence with the screen displayed on the image receptor. ing. That is, the position of the laser beam and the angle of inclination from the reference optical axis can be determined based on the amount of displacement of the near-field image @15 and the far-field image 6 displayed on the image receptor L4. In addition, in FIGS. 3(a) to 3), C indicates the reference position of the laser beam.

FIG. 3G) shows that both the position and traveling direction of the laser beam are correctly aligned.

FIG. 3(b) shows a state in which the traveling direction of the laser beam is aligned parallel to the reference optical axis, but the laser beam position is displaced from the reference position. Figure 3 (c) is
Although the laser beam is aligned to the reference position, the traveling direction of the laser beam is tilted with respect to the reference optical axis. Figure 3) shows that both the position and traveling direction of the laser beam are shifted from the reference and are tilted from the optical axis.

Next, based on Figures 1 and 2, find the position where the multiple reflected light from the eyepiece is focused, calculate the corresponding object point position when this position is taken as the image point position of the near-field image, and This shows that the field image and far-field image can be measured simultaneously.

The multiple reflection focusing position is calculated using FIG.

Here, rl: Lens entrance surface curvature r2: S/Z exit surface curvature d: Lens thickness n: Lens refractive index fz: Lens focal length f2': Multiple reflected light condensing position, f! The optical path of # is 0→P -I Q-4R→S→
It shall be OI.

First, assuming that the eyepiece lens is a thin lens, fz is given by the following equation.

1/f2=(nt) (1/r, -1/r2)
tt+Furthermore, in the case of a plano-convex lens, r1=ψ, so fz ;= -ra/(n-1)
(2).

Next, the multiple reflection focal point position is determined using the tABcD matrix.

where h: height of the optical axis of the lens entrance surface h's light at the lens exit surface d=0
Then, (Equation 31 becomes the following equation.

Since the eyepiece lens has a Keplerian type, 0 is given by the following equation.

#=h/fz (5) Here, from equation 121, f2=-rz/(nu), so equation (5) becomes θ''=-h(n-1)/rz.

Substituting equation (5) into equation (4) yields the following equation.

h””h 16)
a' = 2h (1-2n)/r2 (71, therefore, fz'=h'ρ' = r2/2(1-2n)
(8) At this time, the observation position of the near-field image is determined by the following equation.

13 = Cft + fz )/M - fz'/ M2
(9) Here, M=fz/flQI According to the above analysis, if the image sensor [3 is placed at the position determined by formula (8), the near-field image at the position determined by formula (9) as well as the far-field image will be obtained. It can be seen that it is possible to receive light.

In the above-described embodiment, the near-field image and the far-field image are adjusted by adjusting the reflectance ft of the non-reflection deposited film applied to the eyepiece.

〔Effect of the invention〕

As explained above, the present invention arranges an image sensor at the multiple reflection condensing position of the eyepiece lens, and enables simultaneous measurement of a near-field image and a far-field image using a pair of image sensor and image receptor. This has the effect of reducing the number of parts constituting the device and making the device smaller and cheaper.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of an embodiment of the present invention, FIG. 2 is an enlarged view showing the multiple reflection condensing path of the eyepiece, and FIG. FIG. 4 is a block diagram of the conventional example of the company, which shows the displacement from the reference position and the tilt state in correspondence with the screen displayed on the image receiver. 11... Objective lens 12... Eyepiece lens 1
3... Image sensor t4... Image receptor 15...
・Near field gI116...Distant field image χ, D@
Ward rIQ

Claims (1)

[Claims] A Keplerian image transfer optical system is formed by the objective lens and the eyepiece, and an image sensor is arranged at the multiple reflection focusing position of the eyepiece, and the near-field image and far-field image received by the image sensor are A laser alignment measurement device characterized by comprising an image receptor that simultaneously displays an image and an image.