Home-made Microscope Course Presentation

   The earliest microscopes were manufactured in the late 16th century in the Netherlands. The inventor was As. Janssen, a Dutch spectacles merchant, or another Dutch scientist Hans Lippershey, who created a simple microscope using two lenses. However, they did not make any significant observations with these instruments.
 Later, two people began to use the microscope in science. The first was the Italian scientist Galileo. He observed a kind of insect through the microscope and described its compound eyes for the first time. The second was the Dutch linen merchant, Antoni van Leeuwenhoek (1632-1723), who learned to grind lenses himself. He first described many microscopic plants and animals that are invisible to the naked eye.
 In 1931, Ernst Ruska developed the electron microscope, which led to a revolution in biology. This enabled scientists to observe objects as small as one millionth of a millimeter. In 1986, he was awarded the Nobel Prize.

Objective of the experiment: To understand the structure of the microscope.

 An optical microscope consists of an eyepiece, objective lens, rough focusing screw, fine focusing screw, press, aperture, diaphragm, light-guiding device, light-guiding device converter, mirror, stage, arm, tube, base, condenser, diaphragm, and aperture.

Experimental Report: Dark-Field Microscopy Dark-field microscopy does not allow transparent light to enter the direct observation system, resulting in a dark field when no object is present. It is impossible to observe any objects. When an object is present, the light diffracted from the object and scattered light are visible against a dark background. In dark-field observation of objects, most of the illumination light is reflected back. Due to the different positions, structures, and thicknesses of the objects (specimens), the scattering and refraction of light exhibit significant variations.

The expression of knowledge: It is usually composed of optical parts, lighting parts, and mechanical parts. Undoubtedly, the optical part is the most critical, which consists of ocular lens" 或 "eye lensandobjective lensComposed. Prior to 1590, Dutch and Italian eyeglass makers had already created similar magnifying devices to microscopes. There are many types of optical microscopes, mainly including bright-field microscopes (common optical microscopes), dark-field microscopes, fluorescence microscopes, phase-contrast microscopes, laser scanning confocal microscopes, polarized light microscopes, differential interference contrast microscopes, inverted microscopes.