An on‐line grid‐gaps inspection system for electron‐gun manufacturing

— An on-line grid gaps inspection system (GGIS) for color-CRT electron-gun manufacturing has been developed. The measuring principle is based on the digital-image-processing technique and incorporates a design of stepping motor motion control. By utilizing the arrangement of stepping path image processing, the measurements for different types of guns and for different gaps on a gun can be effectively executed with higher resolution, and are easily implemented for the purposes of on-line inspection and statistical quality control. Experimental results show that the system resolution is about 8.5–10 μm and the on-line inspection index has been improved to about 120 pieces/hour.