Three-phase code is a general term for the production date, expiration date, and batch number marked on pharmaceutical packaging. It is usually presented on the surface of labels, aluminum foil, and other packaging via spraying, stamping, or laser engraving.
Multiple challenges exist in inspection: Characters are prone to being affected by blurred printing and uneven ink, and the spraying position may shift due to equipment vibration. In production, factors such as changes in light conditions, characters being close in color to the packaging background, or character overlap and残缺 can reduce recognition accuracy. Traditional recognition methods are prone to missed or incorrect readings in high-speed production, and parameters need to be repeatedly adjusted during product changeovers.
