RU2276801C1 - Comparison microscope - Google Patents

Abstract

FIELD: possible use for comparison analysis of objects, in particular, for identification research in criminalistics.

SUBSTANCE: microscope contains comparison branches 1,7, each of which includes first 2 and second 6 objectives, device 3 for measuring zoom-in in form of at least two telescopic Galilean pipes, and also block 10 for observation and registration, block 22 for combining fields of images, positioned between branches 1,7 and block 10. each comparison branch additionally includes diaphragm with variable aperture diameter, positioned between second objective and device for changing zoom-in close to the latter. Maximal size of diaphragm aperture is made not less than light diameter of largest lens of Galilean pipes. First objective 2 may be made with possible axial movement.

EFFECT: images, formed by first and second comparison branches, are represented identically.

2 cl, 2 dwg

Description

The invention relates to optical instrumentation and can be used in a comparative analysis of objects, in particular, for identification research in the field of forensics.

A comparison microscope is known, containing two comparison branches, each of which includes a first lens, a magnification changing device, a second lens, an observation and registration unit and an image field combining unit located between the second lenses of the comparison branches and the observation and registration unit. The operation of the comparison microscope is based on the formation by both branches of the comparison of intermediate images of objects in the block combining image fields in a plane aligned with the plane of objects of the observation and registration block. When the image field alignment unit moves in a direction parallel to the optical axes of the second lenses of the comparison branches, the image of the object formed by either the first or second comparison branch is observed and recorded at the extreme positions of the image field alignment block, and in the intermediate positions, parts of the images formed by both branches comparisons. Focusing on the sharpness of images formed by the branches of comparisons is carried out by moving the stage tables along the optical axis of the first lenses [1].

A disadvantage of the known comparison microscope is the difficulty in identifying objects when combining images of their fragments formed by the first and second branches of the comparison, since the brightness of these images is different due to the unequal transmittance of light in the first and second branches of the comparison. This is due to the presence of deviations (tolerances) on the geometric dimensions of the optical and mechanical parts in both branches of the comparison.

A comparison microscope is known, containing two comparison branches, each of which includes a first lens, a magnification change device made in the form of at least two Galilean telescopic tubes, a second lens, an observation and recording unit, and an image field combining unit located between the second lenses of the comparison branches and a monitoring and recording unit. When you move the block combining the fields of images in a direction parallel to the optical axes of the second lenses of the comparison branches, observe and register combined on any fragment of the image of objects formed by both branches of the comparison. When moving the block combining the image fields in the direction perpendicular to the first, observe and register superimposed images of the first and second branches of comparison. Focusing on the sharpness of images formed by the branches of comparisons is carried out by moving the stage tables along the optical axis of the first lenses [2] (the closest analogue).

The disadvantage of this comparison microscope is the difficulty in identifying objects when combining images of their fragments formed by the first and second branches of the comparison, since the brightness of these images is different due to the unequal transmittance of light in the first and second branches of the comparison. This is due to the presence of deviations (tolerances) on the geometric dimensions of the optical and mechanical parts in both branches of the comparison.

The objective of the present invention is to ensure the identity of images formed by the first and second branches of comparison.

The problem is solved in that in a comparison microscope containing two branches of comparison, each of which includes a first lens, a magnification change device made in the form of at least two Galilean telescopic tubes, a second lens, an observation and recording unit, and an image field combining unit, located between the second lenses of the comparison branches and the observation and registration unit, a diaphragm with a varying hole size is inserted in each comparison branch, located between the second lens and the device The property of changing the magnification is close to the last, and the maximum size of the aperture is made no smaller than the light diameter of the largest lens of the Galileo tubes. The first lens is made with the possibility of axial movement.

The analysis of the claimed technical solution showed that the identity of the images formed by the first and second branches of the comparison is ensured by introducing into each branch of the comparison a diaphragm with a varying hole size and placing it between the second lens and the magnification changing device. This allows you to equalize the brightness level of images formed in the branches of comparison, and, accordingly, provides greater identity of these images in comparison with analogues. Performing the maximum size of the aperture opening, not smaller than the light diameter of the largest lens of the Galileo tubes, provides the maximum possible brightness of the image formed by the comparison branch.

The execution of the first lens with the possibility of axial movement allows additional precise focusing on the sharpness of the image by axial movement of the first lens, and by changing the size of the aperture, compensate for the change in brightness of the image caused by the change in the distance between the first and second lenses.

The invention is illustrated by the diagrams shown in figure 1 and 2. Figure 1 shows a functional optical diagram of an embodiment of a comparison microscope; figure 2 - arrangement of beam-splitting sections in the block combining fields (type A, figure 1).

The comparison microscope contains a first comparison branch 1, consisting of a first lens 2 arranged in series, arranged to axially move along the “Z” arrow, a magnification change device 3 made in the form of two Galileo tubes, a diaphragm 4 with a variable opening size, the maximum size of which is made not smaller than the light diameter of the largest lens of the Galileo tubes, deflecting mirrors 5 and the second lens 6. The diaphragm 4 is located near the device 3. Parallel to the first branch 1 of the comparison is located and a second comparison circuit 7 composed of the same elements. In the front focal planes of the first lenses 2 in both branches 1 and 7 of the comparison are the subject tables 8 and 9, respectively.

The comparison microscope comprises a monitoring and recording unit 10, including a lens 11 and a switching mirror 12 installed along its rays. The switching mirror 12 has three fixed positions. In the direction of the rays from the switching mirror 12, in each of its fixed positions, respectively, a visual channel 13 comprising a lens 14 and a binocular system 15, a television channel 16 containing a lens 17 and a television camera 18, and a photographic channel 19 containing a lens 20 and a camera 21 are installed .

Between the second lenses 6 of the comparison branches 1 and 7 and the monitoring and recording unit 10, there is an image field combining unit 22 including a reflective prism 23 consisting of a rectangular prism 24 with reflective faces 25 and 26 mounted at an angle to the optical axis of the second lenses 6, respectively , branches 1 and 7 of the comparison. Prism 24 is glued along face 26 with a rectangular prism 27. Block 22 also includes a dividing prism 28 formed by prisms 29 and 30 with a common beam splitting face 31 inclined to the optical axis of the observation and recording unit 10 and parallel to face 25 of prism 24. Prism 30 is made in the form of a rhombus-prism, the beam-splitting face 31 of which contains three sections. The first section 32 is made in the form of a translucent mirror (figure 2), the second section 33 with a mirror-reflecting surface and the third section 34 with a surface transparent to light. The dividing line 35 of the sections 33 and 34 is perpendicular to the plane of the main section of the dividing prism 28, which is mounted with the possibility of linear movement in the X direction between branches 1 and 7 and can be moved to two fixed positions 36 and 37 in the Y direction parallel to line 35. In FIG. .2 shows the location of the field of view 38 of the block 10 in the first fixed position 36 and in the second fixed position 37 of the prism 28.

The operation of the comparison microscope is as follows.

Two compared objects, for example, bullets, one of which is known and belongs to the bulletproof magazine, and the other is analyzed for the identity of the first, are installed on the stage tables, respectively, 8 and 9. Images of the comparison objects are formed by the branches 1 and 7 of the comparison in the plane of the separation prism 28, coinciding with the focal plane of the block 10 and passing through the dividing line 35 of the sections 33 and 34 of the beam splitting face 31. When the dividing prism 28 is in the first fixed position 36 in the field of view 38 of the block 10 is formed composite image, to the left of line 35 is the left side of the image of the known bullet formed by branch 1, to the right is the right part of the image of the analyzed bullet formed by branch 7.

When sequentially moving the separation prism 28 to the left in the X direction, the image of the analyzed bullet will occupy a larger part of the field of view 38, and when moving to the right, the image of the known bullet.

After the dividing prism 28, the beam of rays passes through the lens 11 and enters the switching mirror 12 in a parallel beam. When the mirror 12 is set to the position shown in Fig. 1 by a solid line, the beam of rays is directed to the television channel 16, where the lens 17 is formed on the photodetector area of the camera 18. images of the known and analyzed bullets, which are viewed on a monitor screen (not shown in FIG. 1) connected to the camera 18. When observed through the visual channel 13 (mirror 12 is set to the position shown by the stroke by the line crossing the optical axis) or the television channel 16 of the images formed by branches 1 and 7, the sharpness of these images is first roughly focused by moving the subject tables 8 and 9. Then, the images are precisely focused by the axial movement of the lenses 2, and their level of brightness is aligned by changing the size of the aperture opening 4 in branch 1 or 7. In this case, the aperture (aperture angle) of the lens 2 and, accordingly, the brightness level of the image formed by it together with the lens 6 change.

To register the received images in the photographic channel 19, the mirror 12 is transferred to the position shown in Fig. 1 by a dashed line that does not intersect the axis of the lens 11. In this case, the lens 20 forms images of objects in the plane of the photographic material of the camera 21.

Thus, the proposed technical solution ensures the identity of the images formed by the first and second branches of comparison.

Information sources

1. Skvortsov G.E. and other microscopes. - L .: Engineering, 1969, p. 396-398, Fig. XVII-2.

2. RF patent No. 2082197, IPC ⁶ , G 02 B 21/18, 1997.

Claims (2)

1. A comparison microscope containing two comparison branches, each of which includes a first lens, a magnification change device made in the form of at least two Galilean telescopic tubes, a second lens, an observation and recording unit, and an image field combining unit located between the second branch lenses comparison unit and the observation and registration unit, characterized in that in each branch of the comparison introduced a diaphragm with a varying hole size, located between the second lens and the device changes increase in the vicinity of the latter, and the maximum aperture size is made not less than maximum lens diameter light pipes Galileo. 2. The comparison microscope according to claim 1, characterized in that the first lens is made with the possibility of axial movement.

Images