Technical parameters of telecentric lens

Date:2017-05-02 Author: Click:

1) High image resolution

The image resolution is generally measured by the CTF (Contrast Transfer Function) which quantifies the existing spatial frequency contrast of the image sensor, and the unit is lp / mm (the number of coupled lines per millimeter). Most machine vision integrators often only gather a large number of cheap low-pixel, low-resolution lenses, and can only produce blurred images in the end. With AFT telecentric lenses, even with small pixel image sensors (such as 5.5 megapixels, 2/3 "), high-resolution images can be generated.

2) Nearly zero distortion

The distortion coefficient is the percentage difference between the physical size and the image sensor image size. Ordinary machine lenses usually have distortions greater than 1-2%, which may seriously affect the accuracy level when measuring. In contrast, telecentric lenses pass strict manufacturing and quality inspection, and strictly control this error to less than 0.1%.

3) No perspective error

When making precise linear measurements in metrology applications, it is often necessary to observe from the standard front of the object (excluding the sides at all). In addition, many mechanical parts cannot be accurately placed, and the measurement time interval is constantly changing. Software engineers need images that accurately reflect the real thing. Telecentric lenses can perfectly solve the above confusion: because the entrance pupil can be located at infinity, only the principal rays parallel to the optical axis will be received during imaging.

4) Telecentric design and ultra-wide depth of field

Bi-telecentric lenses can not only enhance the natural depth of field by using aperture and magnification, but also have unparalleled optical effects of non-telecentric lenses: when the object is moved within a certain object distance range, the imaging does not change, that is, the magnification does not change.