【Line scan camera】Introduction and selection of line scanning lens

In: Lens Wiki On: Tuesday, March 31, 2020 Hit: 3023

Introduction the line scanning lens

line scan lens concept:

Linear CCD lens is a high performance FA lens for image size, pixel size and line sensing series cameras, which can be used for various high-precision inspection.

features of line scanning lens:

1. Designed for high-resolution scanning applications, up to 12K;

2. The maximum compatibility imaging target surface is 90mm, using a longer line scanning camera;

3. High resolution, minimum pixel size up to 5um;

4. Low distortion rate;

5. Magnification rate of 0.2x-2.0x

The choice of line sweep lens matters needing attention

Why consider the lens selection when choosing a camera? Common linear array camera resolutions currently have 1K,2K,4K,6K,7K,8K,12K, and pixel sizes of 5um,7um,10um, and 14um, so the chip sizes range from 10.240mm (1Kx10um) to 86.016mm (12Kx7um).

Obviously, the C interface is far from meeting the requirements, because the C interface can only handle a maximum of 22 mm chip, which is 1.3 inches. The interfaces of many cameras are F, M42X1, m72x0.75, etc. Different lens interfaces correspond to different back focal points, which determines the working distance of the lens is different.

Optical Magnification (Magnification)

Once the camera resolution and pixel size are determined, the Sensor size can be calculated. The chip size divided by the field of view (FOV) equals the optical magnification. Beta = CCD/FOV

Interface (Mount) :

There are mainly C, M42x1, F, T2, Leica, m72x0.75, and so on. After the determination, the length of the corresponding interface can be known.

Back focus (Flange Distance)

Back focus refers to the distance between the camera interface plane and the chip. It is a very important parameter, which is determined by the camera manufacturers according to their own optical path design. Cameras from different manufacturers, even with the same ports, may have different back focuses.

The MTF

With optical magnification, interface, and back focus, the working distance and pitch length can be calculated. So once you've done that, there's another important thing, is MTF good enough? Many vision engineers do not understand MTF, and for high-end lenses it is necessary to measure optical quality.

MTF covers a wealth of information on contrast, resolution, spatial frequency, chromatic aberration and so on, and expresses the optical quality in the center and edges of the lens in great detail. Not only does the working distance and field of view meet the requirements, but the contrast of the edges is not good enough.

Selection of line scanning lens

The DZO eastern normal optical line scan lens supports almost all types of industrial line array cameras from 2K to 16K. High resolution, up to 200lp/mm, ultra-low distortion, and good color correction.

It can meet the requirements of AOI, printing detection, non-woven fabric detection, leather detection, railway track detection, screening and color selection. Moreover, we can provide better lens product selection service for customers and assist them to complete the project better.

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