SU757897A1 - Arrangement for measuring optronic device resolution - Google Patents

Description

The invention relates to a measurement technique, namely, devices for measuring the resolution of optical-electronic devices. five

The known device for measuring the resolution, containing the illuminator, the test object, the collimating lens and recording equipment M. u

Known devices do not allow to measure the resolution at different contrasts of test objects.

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The closest in technical essence to the present invention is a device for measuring the resolution of electron-optical converters at variable contrast, containing an illuminator with adjustable brightness of the working field, a test object, a collimating lens, a rectangular aperture and recording equipment (2) $ 2

However, the disadvantage of this device is the insufficient accuracy of the measurement of the threshold resolution associated with two circumstances. thirty

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First, when forming the image of the test object, a part of the aperture of the collimating lens is used. The aperture changes with a change in contrast, which leads to different distortions of the image of the test object, since different areas of the pupils of the Objectives have different aberrations. In addition, it is impossible to evaluate the performance of the test instrument when using the entire aperture of optics. Secondly, the threshold resolution of optoelectronic devices substantially depends on the average level of illumination (determining the noise level of the radiation detector), the constancy of which with a change in contrast is not provided in this device.

The aim of the invention is to improve the accuracy of measurement of the threshold resolution.

This goal is achieved by the fact that it is equipped with a projecting lens and a beam-splitting prism installed between the illuminator and the collimating object, which forms the inputs of the main and background optical channels, each of which is

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757897

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Condenser, flat mirror and frosted glass are locally arranged, with the main channel ending with a test object, an element combining the main and background channels is installed in front of the collimating lens, and a rectangular diaphragm is made *

movable in a direction perpendicular to the optical axis and the working edge of the beam splitting prism.

In addition, each of the optical channels provides for the installation of ’* neutral filters.

• The drawing shows a schematic diagram of the device.

The device consists of the illuminator 1 with adjustable brightness of the working field 15, installed directly behind the illuminator of the movable rectangular aperture 2, the projecting lens 3 and the beam-splitting prism 4, which forms the inputs of the main 5 and background b optic channels (Optical channels. a light-collecting condenser 7, a flat mirror 8, a neutral light filter 9 and a frosted glass 10, while one ps of the channels — the main one ends with a test object 11.

The output for both channels is a light-collecting element, for example, a translucent plate 12, “

installed before collimating 30

lens 13. On the optical axis of the collimating lens 13 are placed the test device 14 with the recording equipment 15.

The device works as follows 35

in a way.

The luminous flux of the illuminator 1, passing through a rectangular aperture 2, using a projecting lens

3 is directed to the beam-splitting 40 prism 4, and in the plane of the working rib of the beam-splitting prism

4 depicts a rectangular aperture 2. The luminous flux Φ _o falling on the light-multiplying prism 4, дел is divided

its working edge on two light streams f _? and Ф ^, which are reflected from the working faces of the beam-splitting prism 4 and are directed to two optical channels: the main and background. °

In each channel the light flux

with. using a condenser 7 and a flat mirror 8, it is assembled on frosted glass 10, where the exit pupil of a projecting lens 3 is depicted. set test object.

The light fluxes of the 5th 6 channels are combined on a translucent plate 12 and sent to the collimating lens 13. $ 5

Thus, the image of the ground glass 10 of the background channel b is superimposed on the image of the test object 11, which makes it possible to change the contrast of the image of the test object 11.

Changing the contrast of the image of the test object 11 is due to the redistribution of the light fluxes Fu and F ^ over the main 5 and background b channels by moving a rectangular aperture 2 using, for example, a micrometer screw in a direction perpendicular to the optical axis and the working edge of the beam-splitting prism 4. In this case, the image of the diaphragm 2 moves in the plane of the working edge of the beam-splitting prism 4 and the light fluxes F ₅ and F ₆ change, with

_A _ - B - 2x. _. in ^Φ $ ^Ф ° 2В ' ^Ф 6 ^Ф ° 2В

+ 2x

where f _o is the luminous flux incident on the beam-splitting prism 4;

X is the shift of the center of the diaphragm 2 relative to the optical axis,

B - the size of the diaphragm 2 in the direction of movement.

Thus, the proposed device having an optical scheme with dividing the luminous flux into two and directing them into two optical channels, installing a test object 11 in one of them and combining both light streams in front of the collimating lens 13, makes it possible to measure the resolution of optical-electronic devices with variable contrast, using the entire aperture of the collimating lens 13, which provides an increase in measurement accuracy.

Claims (2)

Claim 1, A device for measuring the resolution of optoelectronic devices, containing an illuminator with an adjustable brightness of the working field installed on the optical axis, a rectangular diaphragm, a test object, a collimating lens and recording equipment, which is designed to improve accuracy measurement threshold resolution, it is equipped with a projecting lens and a beam-splitting prism installed between the illuminator and the collimating lens, forming the inputs of the main and background optical channels in which each condenser, flat mirror and frosted glass are sequentially arranged, five 757897 6 In this case, the main channel ends with a test object, an element combining the main and background channels is installed in front of the collimating lens, and a rectangular diaphragm is installed directly by the illuminator, which can be moved in the direction perpendicular to the optical axis and the working edge of the beam-splitting prism. 2. Device by π. 1, characterized in that, with the aim improve the accuracy of imitation workers conditions in each of its optical Channels introduced neutral filters.