JPS6361182A - Target alignment device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a target alignment device, particularly a target alignment device that adjusts the optical axis of a laser beam for laser fusion to a predetermined optical axis for a minute target. Regarding.

[Conventional technology]

The two-get alignment device had a configuration as shown in FIG. That is, a laser beam is focused on a very small alignment target 1 through a condensing lens 2, and the reflected light at this time is transmitted through a transmission mirror 10 that partially transmits the laser beam and an imaging lens 3. The operator manually adjusts the transmission mirror 10 so that the image of the reflected light becomes circular while monitoring the image of the television camera 4. The structure was such that the incident angle was adjusted to match the angle of incidence.

In other target alignment devices, a transmission mirror is fully automatically driven so that the energy density of reflected light is maximized.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional target alignment device, the operator manually performs the alignment, so the method that relies on the operator's subjective opinion does not know the absolute amount of deviation in the incident angle, so one by one, the maximum It is necessary to drive the transmission mirror while determining whether or not this is the case, which also has the drawback of requiring time.

The present invention was made in view of the above problems, and the center of the reflected light image is measured at two points to determine the absolute amount of deviation, and the transmission plate mirror is automatically and automatically adjusted according to this amount of deviation. It is an object of the present invention to provide a target alignment device that can be driven quickly to match the incident angle.

[Means for solving problems]

The target alignment device of the present invention includes an alignment target that indicates a target position, a condenser lens that focuses a laser beam on the alignment target, and an alignment target that obtains an image of reflected light from the alignment target. A television camera placed at a position conjugate to the alignment target image, two optical systems that transmit images before and after the position conjugate to the alignment target image to the television camera, and a A center detector that determines the center of the image, a center difference detector that determines the difference between the determined centers, a transmission mirror that can correct the angle of incidence of the light incident on the alignment target, and drives the transmission mirror. The configuration includes a drive device for causing the

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

The target alignment device shown in FIG. 1 includes a very small alignment target 1 that indicates the position of the target, a condensing lens (LO) 2 that focuses and guides laser light to the alignment target 1, An imaging lens (Ll) 3 for focusing on the television camera 4 placed at a position conjugate with the target image, and an optical system 5 for viewing an image in front of the target image and focusing the image on the television camera 4. and,
The system includes an optical system 6 which looks at the image of the target and then focuses the image on the television camera 4.

Here, these two optical systems 5 and 6 include a lens (Lm) 51, an optical system 2-M1 to M4, and a lens (L4), respectively.
51 and mirrors M5 to M8. These two optical systems 5.6 are arranged to form an image on the television camera 4 at equal pressure #IK in front and rear of the target image.

The target alignment device shown in FIG. 1 includes a center detector 7 for determining the center of the beam from the image obtained by the two optical systems 5.6, and It includes a center difference detector 8 that detects a difference, and a drive device #t9 that drives a transmission mirror 10 that partially transmits the laser beam based on a signal from the center difference detector 8.

Next, how to determine the amount of shift of the transmitting W mirror will be explained using FIG. 3.

Now, the image obtained by the optical system 5 is the same image as the surface SIi, and the center of the image is ("Iyl), and the image obtained by the optical system 6 is the same image as the surface β, and its center is Center of the image ("+7")
, the distance between the focal plane SO of the imaging lens Ll and the surface 81, and the focal plane So and the surface S! Assuming that the distance from

Here, if the amount of deviation (θ, δ) is 0, it can be seen that there is no deviation in the incident angle.

Therefore, the transmission mirror 10 is driven and controlled so that the amount of deviation (θ, δ) becomes zero.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but includes moderate modifications such as, for example, optical systems 5 and 6 having other configurations.

〔Effect of the invention〕

The target alignment device of the present invention measures the center of the image of the reflected light from the alignment target at two points to determine the absolute amount of deviation in the angle of incidence, and automatically adjusts the transmission mirror according to this deviation. Since it can be driven to the correct angle, there is an effect that the incident angle can be set accurately and quickly.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a schematic diagram for explaining a method for measuring the deviation of the angle of incidence in the embodiment shown in FIG. 1, and FIG. 3 is a conventional example. FIG. 1... Alignment target, 2...
...Condensing lens, 3...Imaging lens, 4...
...TV camera, 5.6...Optical system, 7.
...center detector, 8...center difference detector,
9... Drive device, 10... Transmission amount mirror, 51.61... Lens, M1 to M8...
···mirror. Agent: Susumu Uchihara, patent attorney. Nige. (and a small amount of

Claims (1)

[Claims] an alignment target that indicates a target position; a condensing lens for focusing laser light on the alignment target; a television camera disposed conjugately with an image of reflected light from the alignment target; and the alignment target. two optical systems that transmit images before and after a position conjugate to the image of It is characterized by comprising a center difference detector for determining the difference in center position of images, a partially transmissive mirror capable of correcting the angle of incidence of the incident light on the alignment target, and a drive device for driving the transmittance mirror. target alignment device.