The parts of a microscope can be classified into those that belong to its mechanical system and those that belong to its optical design.
Parts of the optical microscope
The mechanical system includes all the structural elements that give stability to the microscope and keep the optical elements correctly aligned.
Base or foot: It is the piece in the lower part of the microscope and on which the rest of the elements are mounted. It tends to be the heaviest part to provide enough balance and stability under the microscope. It is common to include some rubber stops to prevent the microscope from sliding on the surface where it is located.
Arm: The arm constitutes the skeleton of the microscope. It is the middle piece of the microscope that connects all its parts. It mainly touches the surface where the sample is placed with the eyepiece where it can be observed. Both the objective and eyepiece lenses are also connected to the microscope arm.
Stage: This is the surface where the sample to be observed is placed. The set has a hole in the center through which the specimen is illuminated. Usually, two clamps are attached to the location, allowing the sample to be held in a fixed position. Two screws can adjust their vertical position relative to the objective lens to generate a focused image.
Tweezers: The tweezers have the function of keeping the preparation fixed once it has been placed on the stage. Many tweezers like Precision Tweezers, Titanium Tweezers, and Technik Tweezers are used in microscopy
Coarse screw: This screw allows you to quickly adjust the vertical position of the sample relative to the objective. It is used to obtain a first focus that is changed later using the micrometer screw.
Micrometer Screw: The micrometer screw is used to achieve a more precise focus on the sample. Using this screw, the vertical displacement of the stage is adjusted slowly and with great precision.
Revolver: The revolver is a rotating part where the objectives are mounted. Each aim is to provide a different magnification. The revolver allows for a selection of the most suitable for each application. Usually, the revolver enables you to choose between three or four other objectives.
Tube: The tube is a structural piece attached to the telescoping arm that connects the eyepiece to the objectives. It is an essential element to maintain a correct alignment between the optical components.
The optical system includes all the necessary elements to generate and deflect the light in the required directions, thus generating an enlarged image of the sample.
Spotlight or light source: This essential element generates a beam of light directed towards the sample. In some cases, the light beam is first directed towards a mirror, which deflects it towards the model. The position of the focus in the microscope depends on whether it is a transmitted light or a reflected light microscope.
Condenser: The condenser is the element in charge of concentrating the light rays coming from the focus to the sample. In general, the light rays coming from the guide are divergent. The condenser consists of a series of lenses that change the direction of these rays so that they become parallel or even convergent.
Diaphragm: The diaphragm is a piece that allows regulating the amount of light incident to the sample. It is usually located just below the platen. It is possible to vary the contrast with which the model is observed by controlling the incident light. The optimum point of the diaphragm depends on the type of sample followed and its transparency.
Objective: The objective is the set of lenses closest to the sample and produces the first magnification stage. The lens usually has a concise focal length. In modern microscopes, different objectives are mounted on the turret. This allows you to select the appropriate lens for the desired magnification. The magnification of the goal along with its numerical aperture is usually written on its side.
Eyepiece: This is the optical element that provides the second stage of image magnification. The eyepiece enlarges the image that the objective has previously magnified. In general, the magnification provided by the eyepiece is less than that of the goal. It is through the eyepiece that the user observes the sample. Depending on the number of eyepieces, it is possible to distinguish between monocular, binocular, and even trinocular microscopes. The combination of objective and eyepiece determines the total magnification of the microscope.
Optical prism: Some microscopes also include prisms inside to correct the direction of light. For example, this is essential in binocular microscopes, where a prism splits the beam of light coming from the objective to direct it towards two different eyepieces.