Microscopic objectives classified by purpose
Classified by purpose
The use of optical microscopes can be roughly divided into two categories: "biological use" and "industrial use". Objective lenses can also be classified as "biological" based on these two purposes
Use objective lenses and industrial objective lenses. In biological applications, biological specimens are generally placed on a slide and covered with a cover glass for fixation. Due to the need for biological objective lenses to observe samples through a cover glass, an optical system design was adopted that takes into account the thickness of the cover glass (usually 0.17 mm). In industrial applications, it is generally observed in the uncovered state of specimens such as metal mineral slices, semiconductor wafers, and electronic components. Therefore, the industrial objective adopts the optimal optical system design with no cover glass state between the front end of the objective and the specimen.
Classify according to observation methods
Various observation methods have been developed based on the use of optical microscopes, and specialized objective lenses corresponding to these observation methods have also been developed. The objective lens can be divided according to the observation method. For example, "Reflective dark field objective (with a circular illumination path around the internal lens)", "Differential interference objective (reducing internal distortion of the lens and optimizing the optical characteristics combination with differential interference prisms)", "Fluorescence objective (improving transmittance in the near ultraviolet field)", "Polarized light objective (greatly reducing internal distortion of the lens)", and "Phase difference objective (with built-in phase plate)".
Classified by magnification
An optical microscope is a device called an objective converter that installs multiple objectives. In this way, simply rotate the objective lens converter to switch from low magnification to high magnification, easily completing the magnification transformation. So generally, a set of objective lenses with different magnifications are installed on the objective lens converter. Therefore, the product lineup of objective lenses consists of low magnification (5 x, 10 x), medium magnification (20 x, 50 x), and high magnification (100 x) objectives. Among them, especially in high magnification products, in order to obtain high-definition imaging, we have launched a liquid immersion objective filled with specialized liquids with high refractive indices such as synthetic oil and water between the front end of the objective and the specimen. In addition, ultra-low magnification (1.25 x, 2.5 x) and ultra-high magnification (150 x) objective lenses have been launched for special purposes.
