SU1158862A1 - Device for checking angular errors of prisms - Google Patents

Abstract

DEVICE TO CONTROL ANGULAR ERRORS PRISM, containing ALL-ESCAPE ... v- "5-43 I i..f: -M an autocollimator located on the same optical axis and a reflector installed behind a controlled prism, characterized in that accuracy of control, it is equipped with a flat mirror installed between the autocollimator and the reflector in a plane parallel to the optical axis, and the reflector is made in the form of a n {ism-trihedron and is set so that its vertex is located on the optical axis.

Description

SP

00 00 The invention relates to a measurement technique and can be used to control the angular errors of e-mirror-prism elements in a machine tool industry. A device for controlling angular errors of prisms, containing an autocollimator, an optical reflective unit made in the form of two fastened to each other at an angle of 90 flat plates, one of which is specular and the other is a beam-splitting coating. The disadvantage of this device is relatively low control, due to the error of bonding at an angle of 90 two plane-parallel plates and the wedge shape of a parallel-parallel plate with a beam-splitting coating. Closest to the present invention is a device for monitoring angular errors of prisms containing an autocollimator located on the same optical axis and a reflector mounted behind a controlled prism located on a plane-parallel plate, the edge formed by the reflector faces perpendicular to the plane-parallel plate C2. The disadvantages of the known device are relatively low measurement accuracy due to the angular error of the edge formed by the edges of the reflecting prism, perpendicular to the plane-parallel plate, and the relatively low sensitivity of the optical circuit. In addition, the device is difficult to manufacture and the periodic installation of the rib installation necessary for reflecting the prism perpendicular to the plate of the plate is necessary. I The purpose of the invention is to improve the accuracy of prism error control. This goal is achieved by the fact that the device for the angular error of the prisms contains autocol located on the same optical axis. The litator and reflector, installed behind a controlled prism, is equipped with a flat mirror mounted between the autocollimator and the reflector in a film parallel to the optical axis. and the reflector is made in the form of a prism triad and installed so that its top is located on the optical axis. FIG. 1 is a schematic diagram of a device for monitoring angular errors of prisms, with an external angle in FIG. 2 and FIG. 3 is the same for controlling the internal angle in FIG. 4 and FIG. 5 - the same, to control the external angle 45. The device contains an autocollimator 1, a reflector made in the form of a prism-trihedron 2 (ws with us BKP-ISO) and a flat mirror 3. The angle error between the faces g and S of prism 4 is monitored. The device operates as follows (in the case of, for example, controlling the external angle 90 of the prism (Fig. 1). The prism 4 is set before the control begins so that it overlaps the lower half of the light beam exiting the autocollimator 1. The light beam of the autocollimator 1 is directed to the monitored the prism 4 is divided by the prism face 5 into two light beams. The first light beam is reflected from face S and directed onto a flat mirror 3. Since the reflecting surface of mirror 3 is perpendicular to the first light beam, then reflected from it It is reflected in the direction, again reflected from the face 5 of the prism 4 and enters the autocollimator 1, the autocollimation image of the autocollimator grid 1 is built in the focal plane of its objective. working faces of the reflection, directed in the opposite direction, but offset from the original, to the face f of the controlled prism 4, is reflected from the face F and falls on a flat mirror 3. Reflecting from mirror 3, the second light beam returns in the opposite direction, again interacting with the face F of the prism 4 and the faces of the prism-trihedron 2, and gets into the autocollimator 1, the second actolimmation image of the autocollimator grid 1 is built in the focal plane of its lens 1. j two autocollimation images of its grid, and since the first and second light beams are twice reflected from the correspondingly controlled face of prism A, the distance L between the autocollimation images of the grid of autocollets Matora equal to 4 and i, where Act-- deviation (error) of the angle between faces of F 6 and controlled by the prism 4, from 1 - focal length of the object va autocollimator 1 This implies that dividing autocollimator price scale is reduced twice. As a result, the control accuracy is increased. When controlling the internal angle 5 of the prism (Fig. 2 and 3), the device operates as follows. The beam of light of the autocollimator is directed to the controlled prism 4 (Fig. 2), which is installed so that the lower half of the beam of light of the autocollimator 1 falls into the prism 4 and falls on the edge 5, and the upper half of the beam passes over the prism 4. Reflected from the S face The first light beam (bottom half on the main light beam) falls on the face F of the prism 4, reflects from it and directs to the flat mirror 3. Since the reflecting surface of mirror 3 is perpendicular to the light beam incident on it, it is reflected aets backwards again reflected off. of the faces of the F and 5 prisms 4, respectively, and falls into the autocollimator 1, the autocollimation image of the autocollimator grid Q is constructed in the focal plane of its lens Q, the autocollimation position of the autocollimator grid 1 is determined on a scale. (Fig. 3). The second light beam (the upper half of the main light beam) passes over the controlled prism 4, falls on the prism of the trihedron, having undergone reflections from its working faces, is directed in the opposite direction, but shifted from the original, on the edge P of the controlled prism 4, is reflected from the edge F- falls on the face S of the prism 4, reflects from face 6 and falls on the flat mirror 3. Reflected from the flat mirror 3, the second light beam returns in the opposite direction, interacting again with faces 5 and F of the prism 4 and faces prisms- trihedron 2, and gets into the autocollimator 1, the autocollimation image of the autocollimator grid is built in the focal plane of its lens. Since the first and second light beams are twice reflected from the respective controlled faces of the prism 4, the distance D between the autocollimation image of the grid formed by the first light beam, the position of which was determined before the rotation of the prism 4 through 90 °, and the autocollimation image of the grid formed by the second the light beam is also equal to L 4th (L f, where Lo (. is the deviation (error) of the angle between the faces S and P of the controlled prism 4 from 45 °. Consequently, the division value of the scale of the autocollimator 1 is halved. With control The device operates as follows: The light beam of the autocollimator 1 is directed onto the controlled prism 4 (Fig. 4), which is set so that the lower half of the light beam of the autocollimator falls on the edge 5 of the controlled prism 4, and the upper half of the light beam passes over the prism 4. Reflecting from face S, the first light beam (lower half of the main light beam) returns back to the autocollimator 1 and builds an autocollimation image in the focal plane of the objective lens autocollimator grids 1. The second light beam (upper half of the main light beam) passes over the controlled prism 4, falls on the prism-trihedron 2, having undergone reflections from its working faces, is directed in the opposite direction, but relative to the original, on the face F of the prism 4 is reflected from it and falls on a flat mirror 3. Reflected from a flat mirror 3, the second beam returns in the opposite direction, S1 interacts again with the F face of the prism 4 and the faces of the prism-trihedron 2, and gets into the autocollimator 1, build into the focal oh its lens plane autocollimating autocollimator image of the grid 1; Thus, in the focal plane of the lens of the autocollimator 1, two autocollimation images of its grid are simultaneously visible. A turn around the vertical axis of the flat mirror 3 achieves an exact alignment of both autocollimation images in the vertical plane. Rotate the prism 4 around the horizontal axis 180 (Fig. 5) or counterclockwise around the vertical axis 45 °. The prism 4 is set so that in the field of view of the autocollimator 1 both autocollimation images of its grid are visible and the distance between them is measured. In this case, the distance A between the two autocollimating images of the autocollimator grid is also determined by the formula li 4 ьos where bob is the deviation (error) of the angle between faces 5 and F of the controlled prism 4 from 45 °. Improving the accuracy of control due to the lack of error due to inaccurate installation of a controlled prism on the table, as in the proposed device the light beams falling on the controlled faces of the prism are strictly parallel to each other; the possibility of using more accurate autocollimators, such as, for example, AF-2. Moreover, the proposed device is much cheaper and easier to manufacture and improves the quality of control of angular errors of prisms and performance. It does not require highly skilled operator.

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Claims (1)

'DEVICE FOR CONTROL OF ANGLE PRISM ANGLE ERRORS, containing an autocollimator and a reflector located on the same optical axis, mounted behind a controlled prism, characterized in that, in order to increase the accuracy of control, it is equipped with a flat mirror' mounted between the autocollimator and the reflector in a plane parallel to the optical axis, and the reflector is made in the form of a trihedral prism and is mounted so that its vertex is located on the optical axis. 00 s 1158