What is the main features of scanning lens, and what’s the application?

1.What is scanning lens?

According to the application field, it can be divided into industrial grade and consumer grade scanning lens. The scanning lens uses an optical design with no distortion, large depth of field, and high resolution.

  • No distortionor or Low distortion: Through the principle of optical imaging without distortion or low distortion at the front end, the original shape of the photographed object is captured for simulation recognition. In the choice of lens for scanning instruments and equipment, the first choice is no distortion or low distortion lens. Or if you selected a distorted lens, it also can be corrected by a back-end software algorithm to get the target field of view.

                      

  • What is the depth of field or DoF? Depth of field refers to the distance between the front and back of the object that is still clear after the subject is clearly focused. The unit is generally expressed in mm. The depth of field is related to the lens design, focal length, aperture, object distance and other factors. The closer the object distance, the smaller the depth of field, and vice versa. The smaller the focal length, the greater the depth of field, and vice versa. The smaller the aperture, the greater the depth of field, and vice versa. According to the characteristics of the optical lens, in the actual application of scanning recognition, a small aperture design is generally used to increase the demand for large depth of field.

  • What is the resolutionof lens? Unit: mm/lp, It refers to the number of black-and-white line pairs that can be distinguished in each mm, that is the measurement unit. Resolution is a measure of the lens pixel index, refer to the ability to identify object details. High resolution is used for industrial level, and low resolution lens is used for consumption level.

2. How to choose chip for scan recognition product?

There are a lot sensors in the mareket, with various sensing area: 1/4”, 1/3”, 1/2.5”, 1/2.3”, 1/2”. so it can meet different project requirements. High resolution lens is generally used in industrial detection. For consumer application, especially for 2D and 3D scanning recognition. The selected VGA chips, such as ov9282, are not required for the corresponding lens pixels, but the consistency of the lens is required, which is very important for the control of the production process. When lens design is completed, In the mass production stage, the angle of view can be controlled at plus or minus 0.5 degrees, to ensure the minimum deviation.

3. How to select the mount of scanning lens?

Industrial scanning generally adopts C mount, T mount etc. As to consumer product, besides the M12 mount, the scanning lens with mount M10, M8, M7, M6 and M5 are widely used. They can meet the trend of lightweight equipment, and the product appearance design can be favored by consumers.

4.What are the application fields of scanning lens?

Visionlens’ self-developed scanning lenses are widely used in face recognition, QR code scanning, high-speed camera scanning, binocular splicing scanning, 3D scanning recognition, macro scanning, handwritten text recognition, printed text recognition, business card recognition, ID card recognition, business execution recognition, value-added tax recognition, fast photo recognition, barcode scanning.

5. Suggested sensor solutions: OV9282、OV7725.

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