How Do I Choose the Best Binocular Microscope?

A binocular microscope is a microscope that allows two eyes to observe at the same time. With the development of science and technology, people find it inconvenient and awkward to observe with one eye, so a binocular microscope is born, that is, two eyes are observed at the same time, and a trinocular microscope is also used. The third eye is usually used to connect video For imaging equipment, the pictures under the mirror are taken and saved. Binocular observation has become a feature of modern visual instruments, and its role is not to feel tired after working for as long as monocular observation. In large-scale biological microscopes and metallurgical microscopes, binocular oblique observation is generally implemented with a division system.

With the development of science and technology, people find it inconvenient and awkward to observe with one eye, so a binocular microscope is born, that is, two eyes are observed at the same time, and a trinocular microscope is also used. The third eye is usually used to connect video For imaging equipment, the pictures under the mirror are taken and saved. Binocular observation has become a feature of modern visual instruments, and its role is not to feel tired after working for as long as monocular observation. In large-scale biological microscopes and metallurgical microscopes, binocular oblique observation is generally implemented with a division system. The basic principle is to use a prism system to divide the image formed by the objective lens into two left and right, and then use two eyepieces to observe. Microscopes can be divided into biological microscopes, metallographic microscopes, stereo microscopes, polarizing microscopes, etc. according to different types. At first, microscopes can only be observed with one eye, which is the so-called monocular microscope ^.

1. The difference between the magnifications of the two lens barrels is not greater than 2-2.5%;

2. The image formed by the two lens barrels should be consistent in direction and the relative tilt should not be greater than 20 "-30";

3. The optical axes of the two lens barrels should be parallel:

The divergence angle of the two optical axes in the horizontal plane is 40 ";

Convergence angle of two optical axes in the horizontal plane 20 ";

4. The image brightness and field of view of the two lens barrels should be the same.

In order to purposefully assemble and correct the binocular, the adjustment analysis must first be performed. No matter how many prisms there are in the system, a composite prism can be used. It is not difficult to see that the image division system can turn the light by 60 ° and make it a positive image.

In the left and right lens barrels of the binocular microscope, there are respective image tilts, and there are relative image tilts between them. The binocular microscope only requires such phase object tilts. It can be proved through calculation that the beam splitting prism rotates slightly around the left and right optical axis directions, and the object is most sensitive to tilt ^[2]

The adjustment of the binocular tube can adopt the dovetail slider type, which is equivalent to the hinge in the binoculars. If the gap between the dovetail rail exceeds the requirements, it will affect the smooth movement and the instability of the optical axis. Generally, it must be ground.

In order to meet the requirements of the length of the mechanical barrel and the axis of the lens barrel to the non-verticality of the lower end face of the screw hole of the objective lens, the position of the prism must be reasonably arranged, and the relevant parts must ensure the processing accuracy.

For the correction of an optical system containing multiple prisms, we hope to select one of the prisms, focusing on adjusting the optical axis deviation, and elect another prism, focusing on adjusting the tilt of the image. In this case, we should strive for independence of the work steps. Sex. Generally, the rotation of the prism that is sensitive to the optical axis deviation around the sensitive rotation axis is used to adjust the optical axis deviation, such as the adjustment of the tilt should also be considered.

From the previous adjustment analysis, it can be seen that no matter what direction the spectroscopic prism is rotated, it will cause the displacement of the image point along the vertical axis. However, the adjustment of the image tilt is a problem of the parallel optical path. In the axial plane, no matter the direction and position of the rotation axis, the slight rotation of the prism around the axis will not destroy the corrected image tilt, so it should be corrected first.

Because the correction of the optical axis deviation is performed after the image tilt is corrected, it is necessary to consider that the selected rotation axis should not destroy the corrected image tilt, and it must have a high adjustment sensitivity. The optical axis deviation is expressed by components in two directions, so there is also the problem of independence of adjustment of the two components of the optical axis deviation.

1. For a biological microscope with an oblique tube, when the oblique tube is rotated 360 °, the image center shift on the focal plane of the eyepiece should meet the standard requirements of the microscope, which mainly refers to the problem that the rotating mechanical axis coincides with the optical axis. If the optical axis of the objective lens does not coincide with the rotating mechanical axis, the relative position of the half-pentagonal prism or the binocular coupling disc can be changed to make the optical axis of the entire system coincide with the rotating mechanical axis.

2. Regarding the non-verticality of the axis of the microscope tube to the lower end of the screw hole of the objective lens, it should also meet the standard requirements of the microscope. Therefore, the requirements must be satisfied during the adjustment process, otherwise the entire image plane is not perpendicular to the axis of the lens barrel, affecting observation . In addition to the part processing errors, the deformation of the parts and the correctness of the assembly and correction methods have an impact. During the adjustment process, it can be adjusted with a double tube front mirror or a special instrument ^[3] .