Introduction to the role of the structure of each part of the microscope
1. Eyepiece
The magnification is engraved on the top of the eyepiece, such as 10×, 20×, etc. According to the size of the field of view, eyepieces can be divided into ordinary eyepieces and wide-angle eyepieces. Some microscope eyepieces are also equipped with a diopter adjustment mechanism, and the operator can adjust the diopter for the left and right eyes respectively. Another camera eyepiece (NFK) can be used for shooting.
2. Objective lens
It consists of an array of lenses and is installed on the converter, also known as the objective lens. During the observation process, the selection of objective lenses generally follows the order from low to high, because the field of view of the low-power lens is large, and it is easy to find the specific part to be inspected. The magnification of a microscope can be roughly regarded as the product of the magnification of the eyepiece and the magnification of the objective lens.
3. Concentrator
The function of the condenser lens is to focus the light within the field of view; the iridescent aperture under the lens group can be enlarged or reduced to control the light transmission range of the condenser, adjust the light intensity, and affect the imaging resolution and contrast. When using, it should be adjusted according to the purpose of observation and the intensity of the light source to obtain the best imaging effect.
4. Light source
The earlier ordinary optical microscope used the reflector on the mirror base to reflect natural light or light to the center of the condenser lens as a light source for mirror inspection. Reflectors are composed of a mirror with a flat surface and another concave surface.
Use a concave mirror when no concentrator is used or when the light is strong, and the concave mirror can play the role of converging light; when a concentrator is used or the light is weak, a plane mirror is generally used. The newly produced microscopes generally install the light source directly on the mirror base, and have a current adjustment screw for adjusting the light intensity.
5. Mirror holder
The base part is used to support the stability of the whole microscope.
6. Mirror column
The upright short column between the mirror base and the mirror arm plays the role of connection and support.
7. Arm
The arcuate part at the rear of the microscope is the part to hold when moving the microscope. Some microscopes have a movable tilt joint between the mirror arm and the mirror column, which can adjust the backward tilt angle of the mirror barrel for easy observation.
8. Lens barrel
The cylindrical structure installed at the tip of the mirror arm connects the eyepiece on the top and the objective lens converter on the bottom. The international standard barrel length of the microscope is 160 mm, and this number is marked on the outer shell of the objective lens.
9. Objective lens changer
The freely rotatable disc at the lower end of the lens barrel is used to mount the objective lens. During observation, the objective lens with different magnifications can be exchanged by turning the converter.
10. Stage
The platform below the lens barrel has a circular light hole in the center. For placing slides. The stage is equipped with a spring clamp to fix the specimen, and there is a pusher on one side to move the position of the specimen. Some pushers are also equipped with scales, which can directly calculate the distance moved by the specimen and determine the position of the specimen.
11. Quasi-focus spiral
There are two types of helixes, large and small, mounted on the mirror arm or mirror column. When rotating, the mirror barrel or the stage can move up and down, thereby adjusting the focal length of the imaging system. The large one is called the coarse quasi-focus spiral, and the lens barrel rises and falls by 10mm every time it rotates; the small one is the fine quasi-focus spiral, and the lens barrel only rises and falls by 0.1mm after one revolution. Generally, when observing an object under a low magnification lens, quickly adjust the object image with a coarse quasi-focus screw to make it in the field of view.
On this basis, or when using a high-power lens, fine-tune with the fine-focus screw. It must be noted that the general microscope is equipped with left and right alignment spirals, which have the same function, but do not rotate the spirals on both sides at the same time, to prevent torsion due to uneven strength of both hands, resulting in spiral slippage.
