Optical flaw detection system for glass bottle - uses light sources to sweep bottle surface and compares calculated signal variation speed with preselected number

摘要

The flow detection system consists of optical sweeping of at least part of the bottle surface during an inspection interval and generating a signal whose value depends on the optical characteristics of the swept surface. The speed of variation of the value of the signal is calculated and compared with a preselected number. A signal indicating if the bottle must be rejected is generated as a function of the comparison between the calculated speed change and the preselected number. The appts. system has one or more light sources (12) and photodetectors (14). Light is directed onto the bottle (c), the incident light being deflected by a fault, such as a crack, in the surface by reflection or transmission onto the photodetector. The output signal from the photodetector is fed vin on BC circuit (16) to an amplifier (18) which either detects bright points (non-inverse amplifier) or dark points (inverse high gain amplifier). The amplifier output is fed to a sweeping and maintenance circuit (20) which is supervised by a microcomputer (22). The sweeping and maintenance circuit is connected to an A/D convertor (30) which is coupled to the microcomputer.