An Auto Backlight Screen Inspection Equipment Based on Machine Vision

In the production of LCD backlight screen for smart phone, the quality of backlight screen is one of the important factors for determining the display effect of LCD. Up to date, the quality inspection of backlight screen in workshop mainly relies on manual. In this research, a kind of auto quality inspection equipment for LCD backlight screen was investigated, based on machine vision technology and intelligent robot hand. The auto backlight screen inspection equipment consists of a feeding device, rolling device, the first visual inspection unit, edge pressing device, film-tearing device, the second visual inspection unit, film-coating device and the auto-sorting system. The equipment can inspect intelligently the defects such as no light, light eye, white spot, white shadow, uneven brightness, light-leaking, displacement, deformation, dust and scratch. The online testing results showed that the detection efficiency of the machine vision inspection equipment could be up to 5 s/p and the omission percent was lower than 3%. The qualified percent of the equipment is comparable to manual detection, while the detection efficiency of the equipment is more than 3 times that of artificial detection. The function of this auto inspection equipment meets well the demands of quality managing in production line of LCD backlight screen.