Optical lens is an indispensable part of the machine vision system, which directly affects the quality of the imaging quality and affects the implementation and effect of the algorithm. The high precision optical waveplate can be divided into short-focus lens, medium-focus lens and telephoto lens from the focal length; wide-angle and standard from the field of view, [telecentric optical lens]; fixed aperture fixed-focus lens on the structure, manual aperture Focus lens, auto iris fixed focus lens, manual zoom lens, auto zoom lens, auto iris power zoom lens, electric three variable (aperture, focal length, focus variable) lens. Optical lenses are widely used for object reflection detection with extremely high reflectivity, such as metal, glass, film, wafer, etc.
The telecentric optical lens is mainly designed to correct the parallax of the conventional optical lens. It can be within a certain object distance, so that the image magnification will not change with the object distance. The situation that is not on the same surface is a very important application.
The closer the target object of a normal optical lens is to the lens (the shorter the working distance), the larger the image will be. When using a normal optical waveplate manufacturer for dimensional measurement, there are the following problems:
1) The magnification is different because the objects to be measured are not in the same measurement plane;
2) Large lens distortion
3) Parallax is also when the object distance becomes larger, the magnification of the object also changes;
4) The resolution of the lens is not high;
5) Uncertainty of the edge position of the image due to the geometrical characteristics of the visual source.
The [telecentric optical lens] can effectively solve the above problems of the ordinary lens, and there is no judgment error of this nature, so it can be used in high-precision measurement, measurement and measurement. The telecentric lens is a high-end optical lens that usually has superior image quality and is especially suitable for dimensional measurement applications.
No matter where, at a certain working distance, there will be the same magnification after refocusing, because the large field of view of VUV grade LiF optics is directly related to the proximity of the lens of the lens. The larger the lens size, the more needed The bigger the scene. Telecentric measuring optical lenses provide superior image quality with smaller distortion than traditional fixed-focus lenses. This optical design makes the image surface more symmetrical and can be precisely measured with software.
Common lens advantages: low cost, practical, and versatile.
Common lens disadvantages: Magnification will change, with parallax.
Ordinary lens application: imaging of large objects.
Advantages of the telecentric lens: The magnification is constant, does not change with the depth of field change, and has no parallax.
Disadvantages of telecentric lenses: high cost, large size and heavy weight.
Application of telecentric lenses: in terms of weights and measures, based on CCD measurements, microcrystals.