Explanation of the structure of the optical microscope section
1. Mechanical part: The mechanical part of the microscope includes components such as the mirror base, lens tube, objective converter, stage, thruster, coarse adjustment handwheel, fine adjustment handwheel, etc.
1) Mirror base: The mirror base is the basic support of a microscope, consisting of two parts: the base and the mirror arm. It is connected to a stage and a mirror tube, which is the foundation for installing optical amplification system components. The base and mirror arm serve to stabilize and support the entire microscope.
2) Lens barrel: The lens barrel is connected to an eyepiece and a converter, forming a darkroom between the eyepiece and the objective (installed under the converter). The distance from the trailing edge of the objective lens to the end of the lens barrel is called the length of the mechanical barrel. Because the magnification of the objective lens is related to a certain length of the lens barrel. The change in the length of the lens tube not only changes the magnification, but also affects the imaging quality. Therefore, when using a microscope, the length of the lens barrel cannot be arbitrarily changed. The standard cylinder length of a microscope is set at 160mm internationally, which is usually marked on the outer shell of the objective lens. There are two types of lenses: single tube and double tube. Single tube lenses can be divided into upright and inclined types, while double tube lenses are all inclined types.
3) Objective lens converter: The objective lens converter can be equipped with three to four lenses, usually three lenses (low magnification, high magnification, and oil lens). By rotating the converter, one of the objective lenses can be aligned with the lens barrel as needed (note that rotating the converter to change the lens should not grip the objective lens), forming an amplification system with the eyepiece.
4) Stage: There is a hole in the center of the stage that serves as a light channel. A spring specimen clamp and a pusher are installed on the stage, which are used to fix and move the position of the specimen, so that the microscopic examination object is precisely located in the center of the field of view.
5) Pusher: It is a mechanical device used to move specimens. It is composed of a metal frame with two push tooth axes, one horizontal and one vertical. A good microscope has graduated scales engraved on the vertical and horizontal frame rods, forming a very precise planar coordinate system. If we need to repeatedly observe a certain part, we can record the values of the vertical and horizontal scales, and move them to the same values in the future to find them.
6) Coarse adjustment handwheel (coarse spiral): The coarse adjustment handwheel is a machine that quickly moves and adjusts the distance between the objective and the specimen.
7) Fine adjustment handwheel (fine spiral): With a coarse adjustment handwheel, the focal length can only be roughly adjusted. To obtain the clearest image, a macro spiral is needed for fine adjustment.
