The wide application of machine vision systems is an inevitable result of the development of industrial automation. As a key component of machine vision systems for high-precision inspection and measurement, telecentric lenses have irreplaceable advantages under certain conditions, enabling machine vision systems to achieve measurement effect.
1) If the object measured by the ordinary lens is not on the same plane, the magnification needs to be adjusted, and the image magnification of the telecentric lens does not change due to the change of the object distance. Therefore, when detecting objects that are not on the same plane, a telecentric lens is required.
2) The telecentric lens has the characteristic of high depth of field, and what the depth of field reflects is the range of distance that the object can be clearly imaged after the lens is focused. Once the object exceeds the depth of field range of the lens, the image will become blurred, and the high depth of field can still have excellent clarity when observing objects with thickness. Therefore, when detecting objects with thickness, where the thickness is greater than 1/10 of the FOV diameter, a telecentric lens is required.
3) When the observation requires low distortion, the image effect needs to be more consistent, and the defect can only be detected under parallel illumination in the same direction. It is also the ideal choice to use a machine vision system telecentric lens.
4) Since the lens is within a certain range of object distance, the image magnification may not change with the change of object distance, so that there will be no perspective distortion or image position error problems that occur when using ordinary lenses. Then, even if you observe the objects inside the deep hole, you can clearly see it. Therefore, when detecting three-dimensional objects or apertures, telecentric lenses are more suitable.