The microscope uses the magnifying imaging principle of the convex lens to magnify the tiny objects that cannot be distinguished by the human eye to the size that the human eye can distinguish. ), and their magnification power is represented by the angular magnification M.
Because the opening angle of the same object to the eye is related to the distance of the object from the eye, it is generally stipulated that the magnification of the image at a distance of 25 cm from the eye (photopic distance) is the magnification of the instrument. The viewing angle of a microscope is usually very small, so the ratio of viewing angles can be replaced by the ratio of its tangents.
The microscope is one of the greatest inventions of the 20th century. Before it was invented, human perceptions of the world around them were limited to what the naked eye could see with the naked eye, or with the help of a hand-held lens.
Microscopes have opened up a whole new world to human vision, seeing for the first time hundreds of "new" tiny animals and plants, as well as the interiors of everything from the human body to plant fibers. Microscopes also help scientists discover new species and help doctors treat diseases.
The first microscopes were made in the Netherlands in the late 16th century. The inventors were Yas Jansen, a Dutch optician, or another Dutch scientist, Hans Lipperch, who built simple microscopes with two lenses, but did not make any significant observations with these instruments.
The imaging principle of the microscope
2018 05/22