In the machine vision inspection system, optical lenses are needed to capture images. In order to meet the requirements of high precision, fixed focus lenses, 4K zoom lenses, and double telecentric lenses are often used. We all know that the characteristics of telecentric industrial lenses are that the distortion rate is low, and the magnification will not change due to the change of the object distance within the depth of field range. Bi-telecentric lens is a category of telecentric lens, which combines the optical path design of object-side telecentricity and image-side telecentricity. In industrial inspection, is the imaging effect of bi-telecentric lens better?

The double telecentric lens is a high-resolution lens that supports dual-camera work, has double magnification, and can achieve nearly zero distortion. In the detection of high-precision large workpieces, the imaging effect is better, and the detection can be completed at one time.

When the conventional industrial lens is shooting, the distance between the measured object and the lens is inconsistent, which will cause different magnifications. When measuring, there will be large distortion, visual focus error, and low resolution. The bi-telecentric lens is parallel light entering and exiting. Within a certain object distance range, there will be no situation where the near and far are small. It can effectively solve the problems of conventional industrial lenses, such as the change of magnification with the object distance, low resolution, and small depth of field.

Comparison of imaging effects between double telecentric lenses and conventional lenses:

1. Tool defect detection

Double Telecentric Lens Shooting                                Regular Lens Shooting

Under the same shooting conditions, due to the visual focus error of the conventional lens, it affects the extraction of the edge of the tool, and the image accuracy is not high. The bi-telecentric lens can ensure that the captured tool outline is clear and the data is accurate, and there is no need to do too much correction to the image.

2. Gear visual inspection

Double Telecentric Lens Shooting                             Regular Lens Shooting

For conventional lens shooting gears, the inner wall of the round hole is visible, the entire gear is raised along the center, the aperture and outer edge data are unreal, and it is not easy to judge the edge. The optical path of the double telecentric lens is a parallel light design, which can filter out the diffuse reflection light source. Using the telecentric lens to shoot the gear, the inner edge of the round hole of the gear and the edge of the outer gear are clear and the data is true.

The double telecentric lens brings great advantages for precise positioning and high-quality image acquisition, which fully meets the requirements of modern industrial inspection and is a high-quality solution in high-precision inspection.