The function of the structure of each part of microscope
1. Eyepiece
Magnification, such as 10×, 20×, etc., is engraved above the eyepiece. According to the size of the field of view, eyepiece can be divided into ordinary eyepiece and wide-angle eyepiece. The eyepiece of some microscopes is also attached with a visibility adjustment mechanism, so that the operator can adjust the visibility of the left and right eyes respectively. Another camera eyepiece (NFK) can be used for shooting.
2. Objective lens
It consists of arrays of lenses and is installed on the converter, also known as the objective lens. In the process of observation, the selection of objective lens generally follows the order from low to high, because the low-power lens has a large field of view, which is convenient to find the specific part to be detected. The magnification of microscope can be roughly regarded as the product of eyepiece magnification and objective magnification.
3. Concentrator
The function of the condenser lens is to focus the light in the field of view; The iris diaphragm below the lens group can be opened up and narrowed down to control the light passing range of the condenser, adjust the light intensity, and affect the resolution and contrast of imaging. When used, it should be adjusted according to the observation purpose and the intensity of light source to get the best imaging effect.
4. Light source
Earlier ordinary optical microscopes reflected natural light or light to the center of the condenser lens as the light source for mirror inspection with the help of the reflector on the mirror base. The reflector is composed of a plane and another concave mirror.
Concave mirror is used without condenser or when the light is strong, and concave mirror can converge the light; When a condenser is used or the light is weak, a flat mirror is generally used. Newly-produced microscopes generally have a light source directly mounted on the mirror base and a current adjusting screw for adjusting the light intensity.
5. Mirror seat
The base part is used to support the stability of the whole microscope.
6. Mirror column
The upright short column between the mirror seat and the mirror arm plays the role of connection and support.
7. Mirror arm
The arched part behind the microscope is the part to hold when moving the microscope. Some microscopes have a movable tilting joint between the lens arm and the lens column, which can adjust the backward tilting angle of the lens barrel for easy observation.
8. Lens barrel
A cylindrical structure installed at the front end of the mirror arm, with an eyepiece connected on the top and an objective lens converter connected on the bottom. The international standard tube length of microscope is 160 mm, and this number is marked on the shell of objective lens.
9. objective lens converter
A freely rotatable disk at the lower end of the lens barrel, used to install the objective lens. When observing, change the objective lens with different multiples by rotating the converter.
10. Stage
The platform below the lens barrel has a circular light hole in the center. Used for placing slides. The stage is equipped with a spring clip to fix the specimen, and one side has a propeller to move the position of the specimen. Some pushers are also attached with scales, which can directly calculate the moving distance of the specimen and determine the position of the specimen.
11. Quasi-focus spiral
Two kinds of screws, large and small, mounted on the lens arm or the lens column can move the lens barrel or the objective table up and down when rotating, thus adjusting the focal length of the imaging system. The big one is called coarse quasi-focus spiral, and the lens barrel rises and falls by 10mm； every time it rotates; The small one is a fine quasi-focus spiral, and the lens barrel can only be raised and lowered by 0.1mm by rotating once. Generally, when observing an object under a low power lens, the coarse quasi-focus spiral is used to quickly adjust the object image to make it in the field of vision.
On this basis, or when using high power mirror, fine-tuning with fine-focus screw. It must be noted that general microscopes are equipped with left and right sets of quasi-focus screws, which have the same effect. However, do not rotate the screws on both sides with both hands at the same time, so as to prevent the screws from slipping due to torsion caused by uneven strength of both hands.
