SU758043A1 - OPTICAL DEVICE 1 - Google Patents

Description

The invention relates to an optical instrument and is intended for the radiation of stationary and non-stationary processes. It will find application in determining the structure of transparent inhomogeneities (gas flow, plasma, glass, etc.) and for measuring the deflection angles of rays that have passed through inhomogeneity.

A shadow device is known, consisting of an illuminator (light source, condo — sor), entrance slit, main lens, Foucault knife, and a system for observing a shadow pattern (photographic lens, screen, or photographic film) M.

Due to the fact that the investigated heterogeneity in such a shadow device is illuminated by a converging beam of rays, there are known difficulties in interpreting shadow patterns, complex processing methods are required, which leads to an increase in the errors in determining the heterogeneity parameters. Besides.

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such a device is sensitive to deviations of light rays only in one direction, i.e. in the direction perpendicular to the edge of the Foucault's knife.

Known as the shadow device, in Ko ⁵ torus heterogeneity rayed

a parallel beam of light £ 2].

It contains the illuminator, the entrance slit located along the light rays, the collimator lens, the lens of the receiving part, visualizing the Foucault's knife-shaped diaphragm, the shadow pattern recording unit. The shell is placed in the focal plane of the collimator lens, and the Foucault knife in the focal plane of the lens receives the ^15th part.

For a comprehensive study of static transparent discontinuities, which usually deflect light rays in different directions and at different angles, it is necessary to jointly rotate the entrance slit in a Foucault knife, and also produce a different overlap of the image of the entrance slit with a Foucault knife. This is yav3 75 80 *

This is a significant drawback, since it reduces the accuracy of parameter determination due to the fact that individual measurements (at different angles of rotation of the system slot — Foucault's knife) are spaced apart in time, r, e. under different external conditions (for example, in the presence of vibrations). In the study of rapidly changing inhomogeneities, such as, for example, the motion of a shock wave in a shock tube, ₁₀ this drawback becomes fundamental, as the frequency of inhomogeneity parameters from experiment to experiment is low.

The aim of the invention is * higher than _{15 the} accuracy of determining the static and dynamic parameters of heterogeneity.

This is achieved in that before the entrance slit and behind the viewing aperture administered respectively on the input ₂ and the output hydrochloric prismatic reflective units of four rectangular prisms each leg sides which form a rectangle whose center is aligned with the optical axis, and its _{May 2}

the plane is perpendicular to it, and the mirror hypotenuse faces are facing the lenses and deployed to the same faces of the adjacent prisms at an angle of 90 °, an additional slot is installed in the plane of the entrance slit, and the light sources in the illuminator are located on the mirror images of the optical axis with an input prism block the ability to move in a plane perpendicular to the optical axis, and in the plane of the imaging diaphragm placed Foucault's auxiliary knives, overlapping images of light sources, the image emye lens receiving part.

The scheme of the proposed optical device is given in the drawing.

The device consists of an illuminator that includes light sources 1, 2, 3, and 4 and capacitor systems 5, 6, 7, and 8.

In the course of the rays from the light sources, there is an input reflective prism block 9, main 10 and additional 11 entrance slots, swivel mirror, 12, collimator lens 13, camera 14. with heterogeneity under study, receiving lens 15, swivel, mirror 16, main and auxiliary Foucault's knives 17, 18, 19 and 20, the output reflective prism unit 21. The block for registering shadow patterns includes photographic lenses 22, 23, 24 and 25 and receivers (photographic lenses—

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ki, screen, photocells) 26, 27, 28 and 20. The input 9 and output 21 reflective prism blocks each consist of four rectangular prisms, their leg faces form a rectangle whose center is aligned with the optical axis, and its plane is perpendicular to the optical axis, except for Moreover, in each prism block, rectangular prisms' are located so that the mirror hypotenuse faces face the Lens and are turned towards the same faces of the adjacent prisms at an angle of 90 °. The light sources 1-4 in the illuminator are mounted on the mirror images of the optical axis by the input prism unit 9 with the ability to move in a plane perpendicular to the optical axis.

The optical device works as follows.

Light sources 1–4, located on the mirror images of the optical axis by the entrance prism unit 9, are fixed by condenser systems 5–8 separately to the upper and lower halves of the entrance slits 10 (main slit) and 11 (additional slit). The entrance slits thus equipped with the aid of a pivoting mirror 12, lenses 13 and 15, and a pivoting mirror 16 are depicted on Foucault knives 17-20. The output reflection unit 21 directs the light beams into the shadow card recorder, including photographic lenses 22-25 and receivers 26 - 29. Thus, in the receiving part of the optical device nablyuda4 ₀ are four shadow pictures which are recorded by receivers 26 - 29.

When determining the static parameters of heterogeneity, shadow patterns are configured in various ways, i.e.

45 Foucault knives can be located in different directions, from different sides of the image of the slots and overlap them in different ways. In addition, the opportunity provided; different focusing, i.e., focusing ₅₀ ki of each frame on its own subject plane in the studied heterogeneity. Photographing shadow patterns with different initial settings is performed while simultaneously running all four ₅₅ light sources. The joint processing of the pictures thus obtained allows more precisely than in the known device to determine the values of its static parameters.

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In the case when dynamic parameters are determined by modifying inhomogeneities, the launch of sources

light is not produced at the same time, but

through given using for example 5

block delay signal of the time interval. Shadow pictures at the same time photograph, as a rule, with the same initial setting of the device. The resulting shadow pattern are exactly sufficient Yu high resolution (resolution limited here only the intensity of the light sources rather than the device structure), and therefore a high spatial resolution, and the time interval ¹⁴ between them strictly stable (due to the lack of mutual influence of far-spaced light sources). All this . leads to an increase in the accuracy of determining the dynamic parameters of heterogeneity.

Claims (1)

Claim ²⁵ Optical instrument for investigating transparent inhomogeneities, containing an illuminator with a light source and a condenser system, entrance slit, 30 collimator lens, camera with heterogeneity under study, receiving lens, visualizing Foucault's knife-shaped diaphragm and block for registering a shadow pattern, from a photographic object — 35 43 6 It is distinguished - with the fact that, in order to improve the accuracy of determining static and dynamic parameters of inhomogeneity, the input and output reflective prism blocks of four rectangular prisms each are inserted in front of the entrance slit and behind the imaging diaphragm, center of which. combined with the optical axis, and its plane is perpendicular to it, the mirror hypotenuse faces: facing toward the lenses and deployed in relation to. an additional slot is installed in the plane of the entrance slit, the light sources in the illuminator are located on the mirror images of the optical axis by the input prism unit with the ability to move in a plane perpendicular to the optical axis, and in the plane of the visualizing diaphragm, auxiliary Foucault knives, overlapping images of light sources formed by the lens of the receiving part.