The main classification, function and application field of microscope
1. According to the number of eyepieces used, it can be divided into monocular, binocular and trinocular microscopes
The price of monocular is relatively cheap, and it can be used as a choice for beginners. Binocular is a little more expensive. When observing, both eyes can observe at the same time, which makes observation more comfortable. For computer use, it is more suitable for those who work for a long time.
2. According to its use and application scope, it can be divided into biological microscope, metallographic microscope, stereo microscope, etc.
1. Biological microscope is the most common kind of microscope, which can be seen in many laboratories. It is mainly used for observation and research of biological slices, biological cells, bacteria, living tissue culture, fluid precipitation, etc., and can be observed at the same time Other transparent or translucent objects as well as powder, fine particles and other objects. Biological microscopes are used by medical and health units, colleges and universities, and research institutes to observe microorganisms, cells, bacteria, tissue culture, suspensions, sediments, etc., and can continuously observe the process of cells, bacteria, etc. multiplying and dividing in the culture medium. It is widely used in cytology, parasitology, oncology, immunology, genetic engineering, industrial microbiology, botany and other fields.
2. Stereo microscopes, also known as solid microscopes and stereo microscopes, are visual instruments with a three-dimensional image and are widely used in biology, medicine, agriculture and forestry, etc. It has two complete light paths, so objects appear three-dimensional when observed. The main uses are: ①As a research and dissection tool for zoology, botany, entomology, histology, archaeology, etc. ②Inspection of raw materials and cotton wool fabrics in the textile industry. ③In the electronics industry, it is used to make assembly tools such as crystals. ④ Inspection of surface phenomena such as pore shape and corrosion of various materials. The surface quality of other transparent substances, and the quality inspection of precision scales, etc.
3. The metallographic microscope is mainly used to identify and analyze the internal structure of metals. It is an important instrument for metallographic research and the key equipment for industrial departments to identify product quality. It is specially used to observe the metallographic structure of opaque objects such as metals and minerals. microscope. These opaque objects cannot be observed in ordinary transmitted light microscopes, so the main difference between metallographic and ordinary microscopes is that the former is illuminated by reflected light, while the latter is illuminated by transmitted light. Not only can it identify and analyze the organizational structure of various metals, alloy materials, non-metallic substances, and some surface conditions of integrated circuits, micro particles, wires, fibers, surface spraying, etc., metallographic microscopes can also be widely used in electronics, chemical and The instrumentation industry observes both opaque and transparent substances. Such as metals, ceramics, integrated circuits, electronic chips, printed circuit boards, liquid crystal panels, films, powders, carbon powders, wires, fibers, coatings and other non-metallic materials. Observe the surface of the object, be reflected by the object surface and then return to the objective lens for imaging. Therefore, it is very important to use a metallographic microscope to examine and analyze the internal structure of metals in industrial production. Stereo microscopes can also be used in industrial production, but they are only used to observe scratches and scratches on metal surfaces. The magnification is generally between 10X-50X, and the magnification of metallography is generally 50X-800X. Up to 2000X.
3. According to the optical principle, it can be divided into polarized light, phase contrast and micro-difference interference contrast microscope, etc.
1. Polarizing microscope is a kind of microscope for identifying the optical properties of the fine structure of matter. All substances with birefringence can be clearly distinguished under a polarizing microscope. Of course, these substances can also be observed by staining, but some are not possible, and a polarizing microscope must be used. It is mainly used to study transparent and opaque anisotropic materials. Generally, substances with birefringence can be observed with this microscope. Birefringence is a fundamental characteristic of crystals. Therefore, polarizing microscopes are widely used in the fields of minerals and chemistry, such as in botany, such as identifying whether fibers, chromosomes, spindle filaments, starch grains, cell walls, and cytoplasm and tissues contain crystals. In plant pathology, the invasion of pathogens often causes changes in the chemical properties of tissues, which can be identified by polarizing microscopy. In human and zoology, polarized light microscopy is often used to identify bones, teeth, cholesterol, nerve fibers, tumor cells, striated muscles and hair.
2. Phase contrast microscope is also called phase contrast microscope. The biggest feature is that it can observe unstained specimens and living cells. These samples cannot be observed under a general microscope, and the phase contrast microscope uses the difference in refractive index and thickness between different structural components of the object to change the optical path difference passing through different parts of the object into an amplitude difference. Observation is achieved by using a condenser lens with a shaped aperture and a phase contrast objective lens with a phase plate. Simply put, it uses the contrast produced by the difference in sample density for observation, so it can be carried out even if the sample is not stained, which greatly facilitates living cells. Therefore, phase contrast microscopy is widely used in inverted microscopes. The objective lens with phase plate is called "phase contrast objective lens", and the word "Ph" is often written on the shell. Phase contrast method is an optical information processing method, and it is one of the earliest achievements of information processing, so it is of great significance in the history of optical development.
3. Differential interference contrast microscopy appeared in the 1960s. It can not only observe colorless and transparent objects, but also present images with a three-dimensional sense of relief, and has some advantages that phase contrast microscopy cannot achieve. more realistic.
4. According to the type of light source, it can be divided into ordinary light, fluorescence and laser microscope, etc.
1. Ordinary light microscopes use ordinary light sources, which are the most commonly used.
2. Fluorescence microscopes use ultraviolet light as the light source, usually to irradiate the object under inspection (fall-beam type) to make it emit fluorescence, and then observe the shape and location of the object under the microscope. Fluorescence microscopy is used to study the absorption and transportation of substances in cells, the distribution and localization of chemical substances, etc.
3. Laser confocal scanning microscope, using laser as the scanning light source, rapidly scans and images point by point, line by line, and surface by plane. Because the wavelength of the laser beam is short and the beam is very thin, the confocal laser scanning microscope has a high resolution, which is about 3 times that of the ordinary optical microscope.
5. According to the position of the microscope objective lens, it is divided into upright and inverted microscopes
The inverted microscope is adapted to the microscopic observation of tissue culture, cell culture in vitro, plankton, environmental protection, food inspection, etc. in the fields of biology and medicine.
Due to the limitation of the characteristics of the above samples, the objects to be inspected are all placed in the petri dish (or culture bottle), which requires the working distance of the objective lens and the condenser lens of the inverted microscope to be very long, so that the objects to be inspected in the petri dish can be directly microscopically Observe and study. Therefore, the positions of the objective lens, condenser lens and light source are all reversed, so it is called "inverted microscope".
Inverted microscopes are mostly used for colorless and transparent live observation. If the user has special needs, other accessories can also be selected to complete the observation of differential interference, fluorescence and simple polarization. Inverted microscopes are more expensive due to their more rigorous production. Seeing that the inverted microscope is widely used in patch-clamp (patch clamp), transgene ICSI and other fields.
6. Digital Microscope
A digital microscope is also called a video microscope, which converts the physical image seen by the microscope into an image on a computer through digital-to-analog conversion.
Digital microscope is a high-tech product successfully developed by combining sophisticated optical microscope technology, advanced photoelectric conversion technology and ordinary TV. Therefore, we can change the research on the microscopic field from the traditional ordinary binocular observation to the reproduction on the display, thereby improving the work efficiency.
Digital microscopes can produce upright three-dimensional images when observing objects. It has a strong stereoscopic effect, clear and wide imaging, and has a long working distance, and it is a conventional microscope with a very wide range of applications. It is easy to operate, intuitive, and has high verification efficiency. It is suitable for the inspection of electronic industry production lines, the verification of printed circuit boards, the verification of soldering defects (printing misalignment, edge collapse, etc.) in printed circuit assemblies, the verification of single-board PCs, vacuum For the verification of fluorescent display VFD, etc., it enlarges the image of the object and displays it on the computer screen, and can save, enlarge and print the picture.
