JPS6016356A - Device for centering lens - Google Patents

Abstract

PURPOSE:To facilitate the observation of an image and the correction of the inclination of the optical axis of a lens in a device for centering the lens through the use of laser light, by adjusting the location of the focus of an objective lens while looking at a figure on a monitoring picture tube. CONSTITUTION:A laser light flux emitted from a laser light source 1 is introduced into a two-axis modulator 3 through a lens system 2, converged by a lens system 4, diverged again, and then introduced into a lens 5 to be tested. The light flux going out of the lens 5 is converged on a plane A and transmitted to a plane reflector 10 through a beam splitter 6, a lambda/4 plate 8 and a corner cube 9. The light flux reflected from the plane reflector 10 is transmitted through the corner cube 9 and the lambda/4 plate 8, reflected by the beam splitter 6, and projected onto a picture tube 11 through an objective collimator lens 7. Two laser beams converted by the two-axis modulator 3 move two-dimensionally as if a two-dimensional diagram were projected onto the picture tube 11. The corner cube 9 can be displaced along the optical axis to shift the focus of the lens 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a lens centering device that uses a laser beam to center a lens.

Conventional technology Conventionally, lens centering was done using a transmissive type or a reflective type decentering method. Centering was performed so that the two sides matched.

Transmission-type eccentricity measurement has disadvantages in that it is necessary to rotate the lens, which requires a rotation means, and it is not possible to adjust the parallelism of the optical axis or to determine the inclination of the optical axis. .

In addition, since reflection type eccentricity measurement can determine the inclination of each surface, centering can be performed by matching the centers of curvature on both sides, but calculations are required to find the center of curvature position during measurement.
It is not easy to match the two images accurately.

The conventional method using a laser beam to determine the optical axis by inserting a lens to be tested between the optical projection system and the image receiving system had the same drawback as the above-mentioned transmission-type eccentricity measurement in that the inclination could not be determined.

Purpose: In view of the above-mentioned circumstances of the conventional lens centering device, the present invention provides a method for focusing the objective lens, which makes it easy to capture images like in transmission eccentricity measurement, and also allows the tilt of the lens optical axis to be easily corrected. It is an object of the present invention to provide an easy lens centering device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail based on embodiments shown in the drawings.

In the embodiment shown in FIG. 1, the optical path of the laser beam emitted from the laser light source 1 includes an optical projection system consisting of a lens base 2, a two-axis conversion modulator 3, and a lens system 4 arranged in this order; A beam splitter 6 is installed in the optical path of the laser beam that enters the test lens 5 through the illumination system and is once condensed on a surface and then becomes diffused light again. A plate 8, a corner cube 9, and a plane reflecting mirror 10 are provided in this order. Plane reflector 1-0
The light beam travels through the corner cube 9 and the λ/4 plate 8 in the opposite direction, and is reflected by the Heems blitter 6. An objective collimator lens 7 and an image pickup tube 11 for forming an image by the objective collimator lens are provided on the optical path of the reflected light. The output of the picture tube 11 is input to a monitor picture tube 12 .

The above 2' Ill conversion modulator 3 converts the incident laser beam into two laser beams having mutually different optical axes according to the signal, and moves each of them two-dimensionally into various shapes. This is something that can be done.

Therefore, the laser beam emitted from the laser light source 1 enters the biaxial conversion modulator 3 through the lens base 2, is converged by the lens system 41, is diffused again, and enters the test lens 5, and then enters the test lens 5. The emitted light beam converges on the A plane, passes through the beam splitter 6, the λ/4 plate 8, and the corner cube 9, and reaches the flat reflector 10. 8 , is reflected by a beam splitter 6 , and is projected onto an image pickup tube 11 by an objective collimator lens 7 .

The two laser beams converted by the two-axis conversion modulator 3 move in two dimensions, so that it appears as if a two-dimensional line diagram, for example a circular line figure, is being projected onto the image pickup tube ]l. The figure is not limited to a circular shape, and may be any shape; the figure shows an example of a circular shape.

In the optical system of this embodiment, since the corner cube 9 can be moved in the optical axis direction, the focal position of the objective collimating lens 7 can be changed thereby.

When the focal position of the objective collimator 7 is moved to the image plane A of the test lens 5 by moving the corner cube 9, the light is collimated and enters the image pickup tube 1, and an image is formed on the monitor tube 12. be observed. Note that the signal from the image pickup tube 11 may be digitized to correspond to the position.

At this time, if one side of the figure to be monitored is blurred, or if the circle is distorted, for example, if the figure is a circle, the test lens 5
Adjust it so that it becomes a perfect circle. By aligning this circle accurately to the center, eccentricity can be adjusted and centering can be performed.

With this device, the image can be formed into any shape, so it is best to make the image easy to see, such as a square or cross shape. Furthermore, since the optical axis is always constant by using the corner cube 9, the reliability of measurement is also improved.

In addition, when the laser beam converted into two axes passes through the test lens 5, it is monochromatic and has a good optical path outside the central axis, as shown in Fig. 2. This makes it possible to adjust the inclination.

Effects As described above, according to the present invention, the focus position of the objective lens can be adjusted while viewing the image of the figure on the monitor picture tube, making it easier to confirm the image, and also allowing the image height to be adjusted freely. Since it is possible to correct the overall tilt of the lens, including the areas where the influence of the tilt of the lens is large at the periphery of the lens.

The present invention can also be applied to optical devices for assembling lenses, centering, measuring resolving power, etc.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the optical system of the lens centering device of the present invention, and FIG. 2 is a sectional view illustrating the position of the laser beam passing through the lens to be tested. J...Laser light source 2-4...Light projection system 3...Laser light modulator 5...Test lens 6...Light beam splitting means (beam splitter) 7...Objective collimator lens 8...・λ/4 plate 9... Corner cube 10...
・Plane reflecting mirror 11...light receiving section (image pickup tube)

Claims (3)

[Claims] (1) A light projection system that condenses the laser beam emitted from the laser light source onto the test object and then converts it into diffused light again, and an objective lens that focuses the diffused light on the light receiving section. In a lens centering device that has an image receiving system consisting of a light receiving section and a light receiving section, and performs centering by aligning the optical axis of the lens to be tested with the optical axis of the laser beam, the laser beam is directed to the above-mentioned light projection system. What is claimed is: 1. A reno centering device comprising: a laser light modulator that can be converted into two axes; and a laser beam centering device that is provided with a laser light modulator that can be converted into two axes, and that moves two-dimensionally the emission directions of two laser light beams emitted from the modulator. (2) A light projection system that makes the laser beam emitted from the laser light source enter the test lens, converge it, and then convert it into diffused light again, and an objective lens and image receiving section that form an image of the diffused light on the light receiving section. In a lens centering device that performs centering by aligning the optical axis of the lens to be examined with the optical axis of the laser beam, the lens centering device has an image receiving system consisting of
A laser light modulator that can be converted into an axis is provided, and the emission directions of the two laser beams emitted from the modulator are moved two-dimensionally, and the laser light modulator is arranged to move two-dimensionally, respectively. A beam splitting means is provided in the optical path of the test lens, a corner cube and a mirror movable in the entrance/exit direction are sequentially provided in the optical path to transmit the beam from the lens to be tested, and the beam reflected by the mirror and returned is divided into the beam splitting means. A lens centering device characterized in that the beam is reflected by the lens and made incident on the objective lens, and the focal position of the objective lens is changed by moving the corner cube. (3) The above-mentioned light-receiving unit is an image pickup tube, and the output of the light-receiving unit is received by the picture tube so that the image formed by the test lens can be monitored. Lens centering device as described.