This case is based in situation as the following. More and more scratches, cracks, fingerprints and other defects detection in recent years. However, it is often too small to detect with naked eye, especially scratches and fingerprint detection on glossy bright surface, metal surface detection, oily cover detection, composite material scratch detection, polymer material scratch detection, etc. All these result in affect the manufacturer reputation and customer experience.

Project Requirement

——

● Detect out the scratches and fingerprint on glossy bright surface of bank card

● Detect out the fingerprint on the oily cover surface (like handbook surface)

Project Challenge

——

The diversification of image areas in industrial detection results in that every image has to be processed to achieve results through various means after do analysis and comprehensive consideration, and there are several difficulties as follows.

● The surface of bank cards and other products is easy to reflect light, and the ordinary light source will reflect the light shadow in the image area

● The shape and direction of the scratches are diversified. Single direction lighting cannot detect all the scratches

● The fingerprint trace is shallow and difficult to be distinguished.

Solution Case

——

⑴Using POMEAS black and white CCD digital camera
 

Advantage: 

● Gigabit Ethernet interface, high speed transmission, no network repeater required, maximum transmission distance up to 100m

● Support ISP functions such as sharpness, noise reduction, gamma correction, black level correction, etc

● Under various scenarios and color temperatures, It behaves in high stability well. It can keep image clear and sharp, real restore image else.

⑵Using POMEAS 0.3X high resolution telecentric lens: PMS-03HT110
 

Advantage: 

● This telecentric lens adopts objective telecentric design, which has features of high DOF, high resolution and low distortion.

● Support C-mount camera with sensor size as 2/3’’

● High position repeat accuracy 

● It can be able to maintain mechanical stability under vibration environment

Lens Parameter

⑶ Match with parallel coaxial light source independently developed by POMEAS (Green)

There are infrared parallel coaxial illumination, green parallel coaxial illumination, blue parallel coaxial illumination, white parallel coaxial illumination. In this case, we adopt green parallel coaxial illumination with special light path design. It can effectively avoid the lamp bead's shadow on the high reflective plane, highlight the object surface tiny unflatness, and reflect the slight scratch and fingerprint trace very clearly, which is convenient for software evaluation.  

Case Demonstration

——

Case Result Showing：

—— 

Fingerprint detection actual image

Scratches detection actual image