Optical part of the optical microscope: it consists of four parts: eyepiece, objective lens, reflector, and condenser.
(1), the eyepiece: mounted on the top of the barrel, composed of two sets of lenses, the role of the eyepiece is to receive the objective lens formed by the inverted solid image and then enlarged into an imaginary image. The eyepiece is engraved with 5 ×, 8 ×, 10 ×, 15 ×, 25 × and other symbols, indicating the magnification. The magnification of the object image of the specimen we observe is the product of the magnification of the objective lens and the eyepiece. If the objective lens is 10 ×, the eyepiece is 8 ×, the magnification of the object image is 10 × 8 = 80 times.
In the eyepiece between the two lenses can be installed on the light bar a short cut hair, as a pointer, to indicate the material to be observed.
(2), objective lens: mounted on the lower end of the barrel in the hole of the objective converter, the general microscope has 2 to 4 objective lenses, each lens is composed of a series of compound lenses, which also has a magnification notation, there are 4 × 10 × 40 × and 100 × 4 × and 10 × objective lens is a low-magnification lens, 40 × is a high-magnification lens, 100 × is an oil lens. Low-magnification lens is often used to search for the object of observation and observation of the specimen in its entirety, high-magnification lens is used to observe a certain part of the specimen or a more subtle structure, oil mirror is often used to observe microorganisms or plants and animals more subtle structure.
(3), concentrator (light collector): located in the carrier table (through the hole) below, composed of two or several mirrors, it can reflect the light reflected from the reflector to focus the light into the objective lens and eyepiece, some of the concentrator can be raised and lowered, to facilitate the adjustment of light, the collector has a retractable garden aperture under the aperture, called iridescent aperture, adjustable collector calibre size and irradiation surface to adjust the intensity of the light (some microscopes have only the shade pole and no light collector). (some microscopes only have a light shield and no light collector). When the light is too strong, the iridescent aperture can be reduced.
(4), reflector: is a microscope observation to obtain the light source of the device, located in the centre of the microscope mirror base, one side of the plane mirror, one side of the concave mirror. Rotate the reflector, can make the outside light through the light collector irradiation to the specimen. When used, strong light with a plane mirror, weak light with a concave mirror.
