The differences and uses of several types of microscopes

Light microscope It was first created in 1590 by Janssen and his son in the Netherlands. Nowadays, the optical microscope can magnify the object 1500 times, and the minimum limit of resolution is up to 0.2 micrometers in the biological microscope. There are many types of optical microscopes, in addition to the general, the main dark-field microscope with a dark-field spotting mirror, so that the illumination of the beam does not come from the central part, but from the surroundings to the specimen of the microscope. Fluorescence microscope is a microscope that uses ultraviolet light as a light source to make the illuminated object emit fluorescence. The structure is: eyepiece, lens barrel, converter, objective lens, stage, aperture, hood, platen clamp, reflector, mirror base, coarse focusing screw, fine focusing screw, mirror arm, mirror column. Dark-field microscope A dark-field microscope is a microscope in which the field of view is dark when there is no object and it is impossible to observe any object because no transparent light is injected into the direct observation system, and when there is an object, the light diffracted back by the object is brightly visible against the dark background, along with the scattered light. When an object is observed in the dark field of view, most of the illuminated light is refracted back, and because the object (specimen) is located in a different position structure, thickness, the scattering of light, refraction and so on have great variations. Phase Difference Microscope Structure of Phase Difference Microscope: Phase Difference Microscope, is a microscope that applies the phase difference method. Therefore, the following accessories are added to the usual microscope: (1) An objective lens with a phase plate (phase ring plate), phase difference objective lens.　(2) A spotting scope with a phase ring (ring slit plate) attached, and a phase difference spotting scope.　(3) Monochrome filter-(green).　(1) Phase plate shifts the phase of direct light by 90° and absorbs and attenuates the intensity of the light. A phase plate is installed at a suitable position on the back focal plane of the objective lens, and the phase plate must ensure the brightness.　(2) The phase ring (ring aperture) is different in size according to the magnification of each objective lens and can be replaced with a turntable.　(3) Monochrome filters are green filters with a center wavelength of 546nm (millimeters). Usually, a monochrome filter is used for observation. The phase plate is moved 90° to see the phase of direct light at a specific wavelength. When a specific wavelength is required, the appropriate filter must be selected, and the contrast is increased when the filter is inserted. In addition, the center of the phase ring slit must be adjusted to the correct orientation before operation, centering the telescope is to play this role components. Video Microscope Combining a traditional microscope with a camera system, monitor or computer to achieve the purpose of magnified observation of the object under test. Video microscope can also be called digital microscope the earliest prototype should be the camera type microscope, the image obtained under the microscope through a small hole into the image of the principle, the projection to the light-sensitive photo, so as to get the picture. Or directly dock the camera with the microscope to take pictures. With the rise of the CCD camera, microscopes could transfer real-time images to a TV or monitor for direct observation, and could also be photographed by the camera.In the mid-1980s, with the development of the digital industry and the computer industry, the functions of microscopes were enhanced through them, making them more simple and easier to operate. By the end of the 90s, the development of the semiconductor industry, wafers require microscopes can bring more with the function, the combination of hardware and software, intelligent, humanized, so that the microscope in the industry has a greater development. Fluorescence microscope In fluorescence microscopy, the specimen must be illuminated in the light, select a specific wavelength of excitation light to produce fluorescence, and then must be in the excitation light and fluorescence light mixed light, a single fluorescence separated for observation. Therefore, in the selection of specific wavelengths, the filter system, become extremely important role.　Fluorescence microscope principle: (A) light source: light source amplitude emission of various wavelengths of light (to the ultraviolet to infrared).　(B) excitation filter source: through the specimen can produce fluorescent light of a specific wavelength of light, while blocking the excitation of fluorescent light is not useful.　(C) Fluorescent specimen: generally stained with fluorochrome.　(D) blocking filters: block out the excitation light not absorbed by the specimen selectively transmitted fluorescent light, in the fluorescent light is also part of the wavelength is selected through. A microscope in which ultraviolet light is used as a light source, causing the illuminated object to fluoresce. The electron microscope was first assembled in 1931 in Berlin, Germany, by Knorr and Haroska. This microscope uses a high-speed electron beam instead of a light beam. Because the wavelength of the electron stream is much shorter than the light wave, so the magnification of the electron microscope can be up to 800,000 times, the resolution of the minimum limit of 0.2 nanometers. 1963 began to use the scanning electron microscope can be seen on the surface of the object's tiny structure.　Microscopes are used to magnify images of tiny objects. They are generally used in the observation of biology, medicine and microscopic particles.　(1) Using the movement of the micromotor stage, with a full eyepiece of the crosshair line, for length measurement.　(2) The use of rotating the carrier stage and the lower end of the eyepiece of the vernier differential angle disk, with the full eyepiece of the address of the word coordinate line, for angle measurement, so that the angle to be measured at one end of the crosshairs and coincide with, and then let the other end of the also coincide.　(3) The use of standard test thread pitch, pitch diameter, outside diameter, tooth angle and tooth shape and other dimensions or shape.　(4) Examine the grain condition of the metallographic surface.　(5) Inspection of workpiece machining surface.　(6) Test whether the size or profile of tiny workpiece is consistent with the standard piece. Polarizing microscope Polarizing microscope is a kind of microscope used to study the so-called transparent and opaque anisotropic materials. Where a birefringent material, in the polarized light microscope will be able to distinguish clearly, of course, these substances can also be used to stain the method of observation, but some of them are not possible, and must be used to polarized light microscope. Polarized light microscope (1) the characteristics of polarized light microscope will change the ordinary light into polarized light for microscopic examination method, in order to identify a substance is monorefractive (isotropic peer) or birefringent (anisotropic). Birefringence is a fundamental property of crystals. Therefore, polarizing microscope is widely used in the fields of minerals and chemistry, and also in biology and botany.　(2) The basic principle of polarizing microscope The principle of polarizing microscope is more complicated, and will not be introduced here. Polarizing microscope must have the following accessories: polarizing lens, polarizing lens, compensator or phase piece, special stress-free objective, rotating stage. Ultrasonic Microscopy Ultrasonic scanning microscopes are characterized by their ability to accurately reflect the interaction between sound waves and the elastic medium of a tiny sample, and to analyze the signals returned from inside the sample! Each pixel on the image (C-Scan) corresponds to a signal feedback from a two-dimensional spatial coordinate point at a specific depth within the sample, and the Z.A transducer with its excellent focusing capability is able to transmit and receive acoustic signals simultaneously. A complete image is thus scanned of the sample, point by point, row by row. The reflected ultrasound is given a positive or negative amplitude so that the time of signal transmission reflects the depth of the sample. A digital waveform on the user's screen shows the received feedback (A-Scan). Setting up the appropriate gate circuits with this quantitative time difference measurement (feedback time display) allows you to select the depth of the sample you want to observe. Dissecting Microscopes Dissecting microscopes, also known as solid microscopes or stereo microscopes, are microscopes designed for different work requirements. When observing with a dissecting microscope, the light entering each eye comes from a separate path, and the two paths are sandwiched at only a small angle, so that the sample can appear three-dimensional when observed. There are two types of light path designs for the dissecting microscope: The Greenough Concept and The Telescope Concept. The dissecting microscope is often used to observe the surface of solid samples or for tasks such as dissections, watchmaking, and the examination of small circuit boards. ***Focusing Microscope A microscope in which the detected light emitted from a point source is focused through a lens onto the object being observed, and if the object is in focus, the reflected light should converge back to the light source through the original lens, which is known as ***focusing, or ***focusing for short. The *** focus microscope [Confocal Laser Scanning Microscope (CLSM or LSCM)] adds a half-reflective half-lens (dichroic mirror) to the optical path of the reflected light, folding the reflected light that has already passed through the lens in other directions, and has a baffle with a pinhole (Pinhole) at its focal point, where a small hole is At its focal point, there is a pinhole with a small hole located at the focal point, and behind the baffle is a photomultiplier tube (PMT). It can be imagined that the reflected light before and after the focal point of the detection light through this set of **** focusing system, must not be able to focus on the small hole, will be blocked by the baffle. So the photometer measures the intensity of the reflected light at the focal point. The significance of this is that a translucent object can be scanned in three dimensions by moving the lens system. Metallographic microscope MC006-5XB-PC metallographic microscope is mainly used to identify and analyze the internal structure and organization of the metal, it is an important instrument for metallographic research in metallurgy, and it is the key equipment for the identification of product quality in the industrial sector, the instrument is equipped with a camera device, which can ingest the metallographic pattern and measure and analyze the pattern, and edit the image, output, store and manage the image and other functions. More domestic manufacturers, a long history. Such as Shanghai Zhongyan Instrument Factory