Product Mirror defect detection

This case study explores the detection of defects on mobile phone screens and frames. The project requires the detection of surface scratches, dents, dirt, oil stains, fingerprints, bubbles and other items.



Product dimension:

140mm*68mm, the detection area is divided into a black screen area and a frame area.

Project Challenges

Mobile phone surfaces are reflective and the color difference between the border area and the screen area is black and white. The difference and contrast between the border and screen results in overexposure issues which might affect defect detection’s outcome. 


As the frame detection area has reflective characteristics, and the screen detection area has reflective characteristics under lighting conditions, a dark area will be generated at the junction, which will significantly impact the uniformity of the light and prevent defects from visibility. 


The location, angle, and severity of the defects in the inspection area are uncertain. Normal optical systems cannot solve all the defects.

Result from ordinary Optical Systems

(Dark corner by the borders) 

Our Solution

✅ Effectively solved the dark area problem at the junction of the border and the area.

✅ Effectively solve the problem of overexposure caused by color difference.

✅ Due to the characteristic of parallel light coaxial reflection, defects (scratches, fingerprints, oil stains) at any angle can be clearly photographed.

Using our BTOS Lens:

BT-2364 (Double telecentric lens) BT-CP64/X (Parallel coaxial light)

Fingerprint Detected

Scratches Detected

Thanks for reading!

Xem thêm nhiều ứng dụng thành công khác

Xem thêm những khó khăn của các ứng dụng Machine Vision và cách các sản phẩm của chúng tôi khắc phục điều đó.

Về Trang Chủ

Tìm hiểu thêm về Techvico và các sản phẩm của chúng tôi.