Essential Parts of a Microscope
The basic design of the microscope has not changed that much
over time. They have evolved, but the basic concept is still the
same. There are several key parts that many types of microscopes
have in common. All of the parts of a microscope must function
properly for the microscope to work well. If one part is
substandard, it can render the microscope useless. The major
parts of a microscope are the lenses, the arm, the tube, the
illuminator, the stage, and the adjustment knobs.
There are two kinds of lenses on a microscope. The eyepiece
lens, also known as the ocular lens is at the top of the
microscope. This is the part that people look through. The
ocular lens is not adjustable on most models. The objective lens
provides much of the microscope's magnification. A microscope
usually has a few different objective lenses that vary in
strength. The objective lenses are contained on a circular part
placed between the eyepiece and the stage. Different objective
lenses are chosen based on their strength. When someone wants to
use a different strength of objective lens, they turn the
circular disk to put another lens over the stage.
Other than the lenses, the other parts of a microscope are the
tube, the arm, the stage, the illuminator and the adjustment
knobs. The tube connects the ocular lens and the objective lens.
People look through the ocular lens and tube and see out of the
objective lens at the bottom. The arm connects the lenses and
the stage. It protrudes to the side and provides a handle to
carry the microscope as well. The stage is where the object is
placed for examination. Stage clamps secure the microscope
slides to the stage. The microscope slides contain specimens
such as blood or other liquids. The illuminator is below the
stage. This part provides light to make the specimen easier to
see. The illuminator is either an actual light or a mirror.
Most microscopes feature two adjustment knobs to help focus the
lenses. The coarse adjustment knob is the larger of the two and
brings the lens and the stage closer together. The fine
adjustment knob is smaller and is used after the coarse
adjustment knob to provide any small adjustments to bring the
item into sharp focus.
These parts of a microscope are common to nearly all models.
Some microscopes use slightly different parts. For example,
electron microscopes use electron beams instead of illuminators.