Microscope objective lenses are classified according to their use
The uses of optical microscopes are broadly classified into two categories: "biological" and "industrial". Objective lenses can also be divided into "biological" and "industrial" objectives according to these two uses.
objective lenses can also be divided into "biological" and "industrial" objective lenses. In biological applications, a biological specimen is usually placed on a slide and covered with a coverslip from above. Since biological objectives require observation of the specimen through the coverslip, the optical system is designed to take into account the thickness of the coverslip (generally 0.17 mm). In industrial use, on the other hand, specimens such as metallic mineral slices, semiconductor wafers, and electronic components are generally observed without being covered. Therefore, the industrial objective lens adopts the optimal optical system design with no coverslip between the front of the objective lens and the specimen.
Classification by observation method
Various observation methods have been developed for the purpose of optical microscopes, and special objectives have been developed to correspond to these observation methods. Objective lenses can be classified by observation method. For example, "Objective lenses for reflective darkfield (ring illumination light path around the internal lens)," "Objective lenses for differential interference (reduction of distortion inside the lens, optimised combination of optical characteristics with differential interference prisms)," "Objective lenses for fluorescence (improved combination of optical characteristics with differential interference prisms)," and "Objective lenses for fluorescence (improved combination of optical characteristics with differential interference prisms). Objective lenses for fluorescence (improved transmittance in the near-ultraviolet field)," "Objective lenses for polarised light (greatly reduced internal lens distortion)," and "Objective lenses for phase contrast (built-in phase plate)," and so on.
Classification by magnification
Optical microscopes have multiple objective lenses mounted on a device called an objective converter. This allows you to switch from low magnification to high magnification by simply rotating the objective converter, making it easy to change magnification. Therefore, a group of objective lenses with different magnifications is usually mounted on the objective converter. For this reason, the lineup of objective lenses consists of low-magnification (5×, 10×), medium-magnification (20×, 50×), and high-magnification (100×) objectives. Among these, especially in the high-magnification products, we have introduced liquid-immersion objectives that are filled with special liquids with high refractive indexes, such as synthetic oil and water, between the front of the objective lens and the specimen in order to obtain high-resolution imaging. We have also introduced ultra-low magnification (1.25×, 2.5×) and ultra-high magnification (150×) objectives for special applications.
