Visual defect detection on mobile phone arc surface

With the continuous expansion of the smart phone market, people are increasingly demanding for the quality and appearance of mobile phones, and more and more personalized innovative thinking. The difficulty has also increased. In the detection of cell phone surface defects, from image acquisition to image processing, visual defect detection at the arc is a difficult point. For a long time, iJUNCO has been at a good level in surface defect detection. Difficult issues have been resolved. The following is a circular arc surface defect detection system developed by iJUNCO for a foreign brand mobile phone.

Detection requirements
Detecting high-precision flaws on the arc surface of the edge of the sandblasted metal mobile phone case.

Arc defect detection on mobile phones

Project Difficulties
The depth of field of an ordinary lens cannot meet the perfect focus of the entire arc surface at one time, and ordinary lenses cannot capture small flaws under the sandblasted texture.

Arc defect detection on mobile phones

Solution
Use a BT series bi-telecentric lens.

Application advantages
1, high resolution, even with a small pixel image sensor can generate high-resolution images, CFT (Contrast Transfer Function) 70lp / mm> 30%;

2. The depth of field is large, and the surface of parts with different object distances can be focused at one time. The general depth of field is ten times that of ordinary lenses.

Application development
For metal shells after surface treatment such as sand blasting, to extract defects such as scratches, stains, impurities, and corrosion on the surface of the shell, a high-transmission bi-telecentric lens is required to achieve this. Surface, etc.) can achieve a good acquisition.