A brief history of the development of microscopic observation techniques

In addition to the development of the structure of the microscope itself, microscopic observation techniques are also constantly innovating: polarized light microscopy emerged in 1850; interference microscopy occurred in 1893; Dutch physicist Zernike created phase contrast microscopy in 1935 He won the Nobel Prize in physics for this purpose in 1953. Classical optical microscopy is only a combination of optical components and precision mechanical components. It uses the human eye as a receiver to observe the magnified image.

 History development

As early as the first century BC, people had discovered that when they viewed tiny objects through spherical transparent objects, they could be enlarged and imaged. Later, we gradually learned about the law of spherical glass surface energy to enlarge the object.

In 1590, spectacles manufacturers in the Netherlands and Italy have created amplification instruments similar to microscopes.

Around 1610, Galileo of Italy and Kepler of Germany changed the distance between the objective lens and the eyepiece while studying telescopes. Electronic scales were used to obtain a reasonable optical path structure of the microscope. Optical craftsmen at the time engaged in the manufacture of microscopes. Promotion and improvement.

In the middle of the 17th century, Robert Hook of the United Kingdom and Leeuwen Hoek of the Netherlands made outstanding contributions to the development of the microscope.

Around 1665, Hook added coarse and fine motion focusing mechanisms, a lighting system, and a workbench that carried specimen specimens in the microscope. These parts have been continuously improved to become a basic part of modern microscopes.

Between 1673 and 1677, Leeuwe Hoek made a single-piece magnifying glass type microscope with high magnification, and the scale manufacturers, of which nine were preserved so far. Hooker and Leeuwenhoek have made outstanding achievements in the study of the microstructure of animals and plants using their home-made microscopes.

In the 19th century, the appearance of high-quality achromatic immersion objective lenses greatly improved the microscope's ability to observe fine structures. In 1827, Amich first used a immersion objective.

In the 1970s, German Abbe laid the classical theoretical foundation for microscope imaging. All these have promoted the rapid development of microscope manufacturing and microscopic observation techniques, and provided powerful tools for the discovery of bacteria and microorganisms by biologists and medical scientists including Koch and Pasteur in the latter half of the 19th century.

In addition to the development of the structure of the microscope itself, microscopic observation techniques are also constantly innovating: polarized light microscopy emerged in 1850; interference microscopy occurred in 1893; Dutch physicist Zernike created phase contrast microscopy in 1935 He won the Nobel Prize in physics for this purpose in 1953.

Classical optical microscopy is only a combination of optical components and precision mechanical components. It uses the human eye as a receiver to observe the magnified image. Later, a photographing device was added to the microscope and the photographic film was used as a receiver that can be recorded and stored. In modern times, photoelectric devices, television camera tubes, and charge couplers are commonly used as receivers for microscopes. Together with microcomputers, they constitute a complete image information acquisition and processing system.

An optical lens made of glass or other transparent material with a curved surface can magnify and image the object. Shanghai Electronic Scales and Optical Microscopy use this principle to magnify tiny objects to a size adequate for human eyes.

Modern optical microscopes usually use two-stage magnification, which is accomplished by objective and eyepieces, respectively. The object to be observed is located in front of the objective lens, and the objective lens is magnified by the first level and becomes an inverted reality image. The real image is then further enlarged by the eyepiece to form a virtual image. The human eye sees a virtual image. The total magnification of the microscope is the product of the magnification of the objective lens and the magnification of the eyepiece. Magnification refers to the magnification ratio of the straight line size, not the area ratio.

The history of microscope development

  Long ago, people knew that certain optical devices could "magnify" objects. For example, in the "Movie Scripture", a concave mirror that can magnify an object is recorded. As to when the convex lens was invented, it may no longer be possible to verify. Convex Lenses - Sometimes people call it a "magnifier" - it can focus on the sun, but also allows you to see the enlarged object, this is because the convex lens can deflect the light. What you see through a convex lens is actually an illusion. Strictly speaking, it is called a virtual image. When the light from the object passes through the convex lens, the light will deflect in a specific way. When we see the light, or unconsciously believe that they are still spread along a straight line. As a result, the object will look larger than it originally was.
A single convex lens can magnify an object by several dozen times, which is far from enough to let us see the details of some objects. In the 13th century AD, glasses made for people with poor eyesight appeared - a lens made of glass. With the disappearance of the darkness that enveloped Europe for a thousand years, various new inventions have emerged. The microscope is one of them. Around the end of the 16th century, the Dutch optician Zaccharias Janssen and his son put a few lenses into a cylinder and found out through the cylinder that the nearby objects were surprisingly large, which is the current microscope and The predecessor of the telescope.
Jensen made the first compound microscope. Using two convex lenses, one convex lens further magnifies the other resulting image. This is the basic principle of a compound microscope. If one of the two convex lenses can be magnified 10 times and the other can be magnified 20 times, then the magnification of the entire lens assembly is 10 x 20 = 200 times.

Composite microscope
In 1665, the British scientist Robert Hooker (people may be more familiar with his other discovery: Hooke's Law) observed the cork slices with his microscope, surprisingly found that there is a "unit" structure. Hook called them "cells." However, the Jensen-era compound microscope did not really show its power, and their magnification was low. The microscope made by the Dutchman Anthony Von Leeuwenhoek (1632-1723) made people eye-opening. Leeuwenhoek learned the technique of grinding eyeglasses since childhood and was keen to make microscopes. The microscope he makes is actually a convex lens, not a compound microscope. However, because of his skill, the magnification of the single-piece microscope was almost 300 times higher than any other microscope.