SU834392A1 - Transparent object optical properties determination method - Google Patents

Description

The invention relates to measuring technique and can be used to study the shape of the light wavefront, for example, when reflected from an optical surface or when light passes through a medium with a transparent inhomogeneity.

A known method for determining the optical properties of an object by the shadow method, characterized in that the object is illuminated with a parallel beam of white light, the image of the light source is fixed in the plane of the imaging diaphragm with subsequent registration of the shadow picture G1].

The disadvantage of this method is the low information content due to the black and white image of the shadow picture.

There is also a method for determining the optical properties of transparent objects using the color shadow method, characterized in that the object is illuminated with parallel light beams of different spectral composition, images of spatially separated light sources are recorded in the plane of the imaging diaphragm of the shadow device, and a shadow picture is recorded [2].

This method does not have sufficient information content and accuracy of measurements, since it does not allow obtaining shadow pictures with maximum color contrast when emitting objects that deform the front of the light wave in an arbitrary way. Such objects include, for example, spatial gas-dynamic flows, the study of which solves the problems of detailed visualization of the flow structure and quantitative measurements. The specified method does not allow to achieve a clear visualization of the details of the investigated object, which reduces the amount of information received, complicates its processing and reduces the accuracy of measurements.

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The purpose of the invention is to increase the information content and accuracy of measurements when controlling the shape of the light front.

This goal is achieved by the fact that in the method for determining the optical 5 properties of transparent objects by the color shadow method, before registering the shadow picture, the relative position of the object and the shadow device is changed by rotating one of them around the 10 optical axis to obtain the maximum color contrast of the shadow picture.

The rotation of the shadow device relative to the object (or vice versa) leads to a change in the orientation of the light beams 15 of different spectral composition relative to the studied object and to a simultaneous color change at all points of the colored shadow caption. In this case, the color contrast of the ²⁰ shadow picture of the object changes with reaching its maximum value, which is due to the dependence of the threshold of color difference and the number of color thresholds on the wavelength. The result is a realization ²⁵ zadiya maximum sensitivity of the color of the shadow of the method and the ability to detect the maximum number of parts of the test object, and that allows you to increase the information content and accuracy of the ²⁰ measurements.

The method can be implemented when measuring using serial shadow devices equipped with means for obtaining a color image

E2 5 with the possibility of rotation of colored lighting and visualizing diaphragms or the object of study. The method is most effective in the study of objects that deform the wavefront of a light wave in an arbitrary way.

Claims (2)

The purpose of the invention is to increase the information and accuracy of measurements while monitoring the shape of the light front. The goal is achieved by the fact that in the method of determining the optical properties of transparent objects by the color shadow method, before registering the shadow pattern, the relative position of the object and the shadow instrument is changed by rotating one of them around the optical axis until the maximum color contrast of the shadow pattern is obtained. The rotation of the shadow device relative to the object (or vice versa) leads to a change in the orientation of the light beams of different spectral composition relative to the object under study and to a simultaneous color change at all points of the colored shadow kaotina. At the same time, the color contrast of the shadow pattern of the object changes with the achievement of its maximum value, which is caused by the dependence of the color difference threshold and the number of color thresholds on the wavelength. As a result, the limiting sensitivity of the color shadow method is realized and the possibility of detecting the maximum number of details of the object under study is realized, and this makes it possible to increase the information content and accuracy of measurements. The method can be implemented when measuring using serial shadow devices equipped with color imaging means with the ability to rotate color lighting and visualizing the diaphragm or object of study. The method is most effective in studying objects that deform the wavefront of a light wave in an arbitrary manner. The invention The method of determining the optical properties of transparent objects by a color shadow method, in which an object is illuminated with parallel beams of light of different spectral composition, captures images of spatially separated light sources in the plane of the visualizing diaphragm of the shadow device, and record a color shadow pattern that differs from informativity and measurement accuracy, before registering the shadow pattern, the mutual position of the object and the shadow instrument is changed, rascha one of them around the op. tic axis to maximize the color contrast of the shadow pattern. Sources of information taken into account in the examination I. Popov S. G, Measurement of airflow. M.-L., Gostekhizdat, 1947, p. 54-101. 2. Vasiliev, L. A, Shadow Methods, M., Science, 1968, p. 46.