Construction and function of optical microscope

Construction and function of optical microscope

A microscope is a device that enlarges objects that are too small to see with the naked eye. Their are 3 types of microscopes; the optical microscope, electron microscope and several types of scanning probe microscope.

The optical microscope, also called the light microscope, uses light and lenses to magnify an image and is used in small sample observation for example cells. It is the oldest type of microscope, developing over the years to maximize resolution and clarity. The two types of optical microscopes are the simple microscope, which uses a single lens, and a compound microscope, which uses many lenses. The compound microscope uses a lens to collect light and another lens to focus that light into the viewer's eye.

The components of the microscope are as follows:
 * Eyepiece - The lens at the top that you look through. It contains 2 or more lenses that focus the image. Usually 10x or 15x magnification
 * Revolving nose piece or turret - Holds 2 or more objective lenses and can be rotated easily to change magnification power.
 * Objective - 1 or more objective lenses that collect light. The lenses are usually in a cylindrical shaped tube. The shortest lens has the lowest power i.e the lowest level of magnification, the longest one is the lens with the greatest power.
 * Focus wheel - These are wheels that move the stage in the vertical plane. There are also wheels for adjusting coarse and focus
 * Frame - The frame consists of the arm, the base and is in essence the bodywork of the microscope. It allows attachment of the focus wheels and the stage
 * Light source - A steady light source (110 volts) used in place of a mirror. Most microscopes do allow light adjustment.
 * Condenser - The function of the condenser lens is to focus the light onto the specimen. To increase the quality the condenser lens may also have filters or a diaphragm
 * Stage - A platform underneath the objective that provides a platform for the slide to be viewed. In the center of the stage is a hole which allows light to pass through. The stage also normally has arms to hold the slide in place.

The power of magnification of an optical microscope is normally 1000x. This type of microscopy is used in microelectronics, nano physics, biotechnology, pharmaceutic research and microbiology.

References: Wikipedia, Google, http://www.microscope-microscope.org/basic/microscope-parts.htm, http://brunelleschi.imss.fi.it/esplora/microscopio/dswmedia/risorse/how_to_make_microscope.pdf,