Metal parts are common products in industrial manufacturing, and they are also an indispensable and important part of industrial manufacturing. However, in the process of processing metal parts, some defects may occur due to technical problems. The surface defects not only affect the appearance, but also affect the performance of the workpiece and reduce the safety of the product.

The material and shape of metal parts are various, and some workpieces have smooth surfaces and high reflection characteristics, which will affect the feature extraction of the measured object during detection. How to obtain images with clear features and high contrast has become a problem that needs to be solved in the detection of reflective metal parts.

Metal parts have various shapes, some of which are parts with a certain thickness and hollow shape characteristics. If this kind of workpiece is shot with an optical system composed of ordinary industrial lenses, irregular longitudinal parallax will be generated at the edge of the inner hole, and the parallax effect of the inner wall will affect the accurate extraction of the contour of the inner hole of the sample, so the measurement size cannot guarantee the measurement accuracy. The optical system composed of telecentric industrial lenses has a full projection shooting effect without vertical and horizontal parallax, which can completely solve the problem of parallax.

When the reflective metal parts are visually inspected, the external light source will have irregular reflections in the metal edge area, and each point of the edge contour will form a diffuse reflection point, so that the contour boundary will form a gray transition zone, which cannot guarantee the contour extraction. precision. The telecentric industrial lens adopts special optical design, which can effectively avoid the effects of various stray reflections, greatly improve the sharpness of the edge of the picture, solve the problem of reflection at the edge of metal parts, and improve the measurement accuracy.

General industrial lenses will have about 1% random distortion, which will lead to image deformation and directly affect the measurement accuracy. The distortion of the telecentric industrial lens is close to zero, which is far lower than that of the general industrial lens, which can reduce the distortion to the greatest extent and reduce the impact on the measurement accuracy.

The distortion rate of Pomeas telecentric industrial lens can reach 0.02% or lower, and it has high resolution, which can well meet the needs of precision machine vision inspection customers.