The way interference measurement of the surface shape of the optical parts

 

The way interference measurement of the surface shape of optical elements includes recording the interference pattern of the photographic through transparent media coverage of registered interferogram in the range of angles fromto+where- angle diffuse scattering of light interferogram;- front of the aperture angle of the analyzing optical system, and further analysis of the light image. The interferogram illuminate the second light source in the range of angles from 0 toand lighting interferogram first and second light sources produce out of phase. The technical result is to expand the functionality of the monitoring method of the interference bands in the diffuse scattering. 1 Il.

The invention relates to the field of interference measurements, and more particularly to methods for increasing the accuracy of determining the coordinates of interference fringes in the images of the interference patterns of the interferogram.

Measurement of the shape of the optical surfaces of the interference method here interferometric method of determining the surface shape of the optical parts is determined only by the accuracy of the coordinates of the bands on the interferogram.

There is a method of multipath interferometry [1], which investigated and exemplary optical surfaces cause the mirror layer with a reflection coefficient close to unity. Due to the changing nature of the sinusoidal interference pattern in sawtoothed increases the accuracy of determining the coordinates of interference fringes.

The disadvantage of this method is the necessity of applying a mirror coating on the analyzed surface before each session control and removal of the coating after the session control.

Also known method [2] to improve the accuracy of the interference measurement by selection of the extrema of the bands due to the nonlinearity of the characteristic curve of the photographic material used for recording the interference pattern.

The disadvantage of this method is the need to increase the exposure time at registration, interferogram.

Closest to the claimed method according to number of essential features and solved technical problem - prototype - is a method [3], including the registration of the interference pattern by photographic, measuring critical anglediffuse rasna the interferogram restrict the interval of anglesand+where- front of the aperture angle of the optical system, and the analysis of the light image. In the above-described light interferogram is delineation (or differentiation) of interference fringes, resulting in improved measurement accuracy.

The disadvantage of this method is the limited functionality, manifested in achieving maximum accuracy of measurements of the coordinates of the bands/100.

The present invention is to enhance the functionality of the method of observation of interference fringes in the diffuse scattering.

This object is achieved in that the proposed method interference measurement of the surface shape of optical elements includes recording the interference pattern of the photographic through transparent media coverage of registered interferogram in the range of angles fromto+where- angle diffuse scattering of light by the interferogram,- front aperture ug additionally illuminate the interferogram second light source in the range of angles from 0 toand lighting interferogram first and second light sources produce out of phase.

Through poorly exposed, almost transparent areas of the interferogram passes and enters the lens, the analyzing system mainly light from the second source, aimed near the normal to the surface of the interferogram. Through much exposed, almost black areas of the interferogram almost is no light from the first or from the second source. Through the areas of the interferogram corresponding to average values for exposures corresponding to the transition between light and dark areas can be diffusely scattered light from the first and from the second source.

In the light interferograms of the first and second light sources in antiphase area of difference between light and dark bands observed flickering. Due to the fact that the eye's sensitivity to flicker, i.e., to cyclic changes in light intensity, an order of magnitude higher than the gradual changes of intensity, increases the accuracy of the interference changes as a whole.

In the present method described is known in the scientific literature some signs, however, the positive effect obyavlenie technical solution meets the criterion of "inventive step".

The implementation of the declared method is illustrated with the help of the device shown in the drawing.

The device comprises a lens 1 with a front aperture angle. analyzed in the light of the interferogram 2, the first and second sources of collimated radiation, including point light sources 3 and 4, placed at the focus of the lenses 5 and 6. The sources and the lenses are arranged so that the interferogram is illuminated by two collimated light beams, and out of phase - when lit, the light source 3, source 4 is extinguished and Vice versa.

Through the light transparent parts of the interferogram light from the first source is virtually no dispersion, not getting into the lens, and these plots observer seem dark. Through highly exposed dark areas interferogram light does not pass at all, so when covering only the first source is observed only areas of transition between light and dark bands, i.e., the border strips.

When the light interferogram second light source at an angle of between 0otothat seems to the observer, the intensity distribution in the bands of the interference pattern corresponds to the school from light and dark bands are presented to the observer shimmering.

The error estimation guidance on the strip is made using ocularocular MOB-1-16x. The standard deviation for guidance on the strip is/100 (in periods of bands) for a known way and/500 for the proposed method.

The proposed method can be used to measure the shape of the test glasses, mirrors, laser resonators, and other precision optical parts.

The use of the claimed invention improves the accuracy of measurement of the surface shape of the optical parts.

Sources of information 1. Skokov I. C. Optical interferometers. - M.: mechanical engineering, 1979, 128 S. - similar.

2. Skokov I. C., Noskov, M. F. Nonlinear photography two-beam interference patterns. - Laboratory, 1984, 1, S. 32-36 - similar.

3. A. C. 1651096. Socks M. F. and the other Way interference measurement of the surface shape precision optical components - prototype.

Claims

The way interference measurement of the surface shape of the optical components, including the registration of the interference pattern by photographic on transparent media, lighting, registered the img> where- angle diffuse scattering of light by the interferogram,- front of the aperture angle of the analyzing optical system, and further analysis of the light image, wherein the light interferogram of the second light source in the range of angles from 0 toand lighting interferogram first and second light sources produce alternately out of phase.

 

Same patents:

The invention relates to the field of measurement technology and can be used for automated measurement of the linear dimensions of various objects, preferably the length and curvature of the pipe, for example, at their workshop repair

The invention relates to measuring equipment

The invention relates to the topography, profilometry

The invention relates to measuring technique and can be used to visualize the profiles of three-dimensional objects

The invention relates to the field of measurement technology and can be used to visualize the profiles of three-dimensional objects

The invention relates to measurement devices, and specifically to the field of contactless optical measurement of the surface shape of optical products, for example, spherical and aspherical mirrors or lenses in terms of optical engineering and laboratory research

The invention relates to measuring technique and can be used to visualize the profiles of three-dimensional objects

The invention relates to the field of measurement technology and can be used to visualize the profiles of three-dimensional objects

FIELD: railway transport; instrument technology.

SUBSTANCE: proposed wear checking system contains optical receiving projection system and converting-and-calculating unit. It includes also car position pickup and car counter whose outputs are connected to inputs to inputs of converting-ands-calculated unit. Optical receiving projection system consists of sets of stereo modules. Rigid structure of each module includes two CCD television cameras and lighting unit. Outputs of stereomodules are connected to corresponding inputs of converting-and-calculating unit. Stereomodules are rigidly installed relative to each other.

EFFECT: enlarged operating capabilities.

3 cl, 2 dwg

FIELD: measuring arrangements.

SUBSTANCE: device comprises unmovable base provided with the first cantilever, two carriages provided with drives controllable with a computer, pickup of linear movements, arrangement for mounting blade and first measuring channel connected with the computer. The first carriage is mounted on the unmovable base and is made for permitting movement parallel to the X-axis. The first measuring passage is defined by the optoelectronic head and units secured to the unmovable base, third carriage provided with an actuator controlled by a computer and pickup of linear displacements, second measuring channel, first and scone markers of the blade with actuating members controlled by a computer, arrangement setting the blade mounted on the first carriage and made for permitting rigid orientation of the blade in the vertical plane, second and third carriages arranged on the first and second cantilevers, respectively, and made for permitting movement parallel to the Z-axis, first and second markers of the blade, fiber optic heads of the first and second measuring channels arranged on the second and third carriages from the both sides of the study blade. The objectives of the fiber optic heads are mounted for permitting triangulation link of the photodetector with the sourced through the blade surface of the blade to be tested.

EFFECT: enhanced efficiency.

6 cl, 7 dwg

FIELD: measuring engineering.

SUBSTANCE: method comprises setting the article to be tested on the working table, moving the nonflatness meter, determining the amplitude of nonflatness, and determining coefficients of nonflatness. The device comprises source of light, multielement photodetector, objective, and computer.

EFFECT: enhanced reliability.

5 cl, 7 dwg

FIELD: measuring instruments.

SUBSTANCE: the interferometer for controlling of the form of prominent, concave spherical and flat surfaces of large-sized optical components has a source of monochromatic radiation, a collimator and an objective, one after another located a beam divider, a flat mirror and an aplanatic meniscus with a reference surface and also an observation branch located behind the beam divider in beam return and a working branch consisting out of a spherical mirror with a compensator which form a focusing system. Depending of the form of a controlled surface focusing of the working branch of the interferometer is executed at replacing the compensator and the basic block of the interferometer which has an illuminating branch. A beam divider, a flat mirror, an aplanatic meniscus and an observation branch relative to a fully stabilized spherical mirror along an optical axis on such a distance at which the beams reflected from the spherical mirror fall on the controlled surface transversely to its surface.

EFFECT: expansion of nomenclature of controlled surfaces, decreasing large-sized dimensions of the interferometer.

2 cl, 3 dwg

FIELD: the invention refers to measuring technique.

SUBSTANCE: the mode of measuring the form of an object includes formation of a light line on the surface of the object with the aid of the light-emitting system lying in the preset cross-section of the object, getting the image of the light line, its processing and definition of the coordinates of the profile of the cross-section of the object. AT that collateral light lines are formed on the surface by turns with the aid of two light-emitting systems illuminating the surface in preset cross-section of the object at different angles in its every point, images of light lines are received. On each of them sites are revealed. A resultant image is compiled out of the images of the indicated sites. According to this resultant image the coordinates of the profile of the cross-section of the object are determined. The arrangement for measuring the form of the object has a light-emitting system optically connected with a photoreceiver and a computing unit. It also has one additional light-emitting system optically connected with a photoreceiver and a commuting unit connected with its input to the computing unit, and with its output - with every light-emitting system. Optical axles of light-emitting system are placed in one plane and located to each other at an angle equal 5-800.

EFFECT: the invention increases accuracy of measuring by way of excluding the distortions of the zone of influence on the results of measuring.

13 cl, 5 dwg

FIELD: measuring equipment.

SUBSTANCE: method includes lighting object by collimated parallel beam of coherent monochromatic light, directed at angle of raising of screw surface relatively to object axis, as which object with screw surface is used, receiving optical image of its profile and following processing of received profile of image to perform further calculations of its parameters, while lighting of object is performed concurrently on two portions by collimated parallel beams of coherent monochromatic light, directed at raising angle of screw surface relatively to object axis, while these two beams are positioned symmetrically relatively to longitudinal axis of object and two images of said profile are received, mutual position of separate elements in which does not depend on presence of vibrations and shaking.

EFFECT: higher quality.

1 dwg, 1 ex

FIELD: measurement technology.

SUBSTANCE: device for automatic measuring coordinates of string plummets of hydraulic structures has reflecting screen, illumination source, two optical systems each of which is blocked with corresponding electro-optical array, device for measuring coordinate of string's projection, digital serial communication desk. Device also has resolver that has in turn two input serial communication desks, which have their outputs connected with controller, and indicator.

EFFECT: high precision of measurement of coordinates of string plummets.

2 cl, 1 dwg

FIELD: measuring engineering.

SUBSTANCE: method comprises directing a coherent light beam at the surface to be tested, producing and recording interferogram of the light path difference, and processing the interferogram. The tested and reference surfaces are exposed to the second coherent light beam, and the second interferogram of the light path difference is created. The second interferogram is provided with the additional light path difference with respect to that of the first interferogram, which is equal to the one fourth of the beam wavelength. The light path difference of the first interferogram is determined at specific points of the surface to be tested from the signal of illumination in one of two interferograms. The device comprises source of coherent light, first filter-condenser, first and second light-splitting units, interferometer composed of tested and reference surfaces, unit for measuring optical length of the beam, first projecting unit, recording unit, observing unit, and unit for processing the interferogram. The device also has two light-splitting units between which two pairs of transparent diffraction lattices are interposed. The filter-condenser, the second light-splitting unit, and λ/4 lattice are arranged in series in the direction of the beam.

EFFECT: enhanced precision.

4 cl, 8 dwg

FIELD: measuring engineering.

SUBSTANCE: method comprises setting the article to be controlled on the movable traverse gear having two extent of freedom, illuminating the surface of the article by light, receiving the light reflected from the surface of the article with the use of a photodetector, moving the article parallel to the X-axis, determining coordinates of the light spots on the photodetectors of the current values of the heights of the article shape, locking the position of the table, scanning the main section of the article shape, comparing it with the reference one , and determining the quality of the article shape. The main section is scanned by moving the article parallel to the Y-axis, when the traverse gear is in a position determined from the formula proposed. The device comprises unmovable horizontal base, vertical cantilever secured to the base, unit for measuring the article shape mounted on the vertical cantilever, two carriages that define a traverse gear and provided with the individual drives controlled by a computer, and pickup of linear movements. The first carriage moves parallel to the X-axis, and the second carriage is mounted on the first one and moves parallel Y-axis.

EFFECT: improved quality of control.

4 cl, 4 dwg

FIELD: measuring engineering.

SUBSTANCE: device comprises housing that receives electric lamp, toroidal lens, conical mirror of ring vision, lens, and scaling grid arranged in series. The device is additionally provided with aperture with ring and central round recesses positioned in front of the lamp, ring and round color filters mounted in front of the recesses, and second mirror cone positioned behind the aperture. The top of the cone points to the lamp. The semi-transparent mirror, color filter, measuring grid, and first TV camera are arranged along the longitudinal axis of the housing behind the lens. The second color filter, second measuring grid, and second TV camera are arranged in series along the perpendicular to the axis of the housing behind the lens.

EFFECT: expanded functional capabilities.

3 dwg

Up!