Abstract: A device for detecting unacceptable defects in a neck area of hollow glass articles transported by a feeding element has a light source spaced from a path of feeding of the articles and arranged to illuminate the neck area of the latter, a projecting element arranged to project an image of the neck area of each of the glass articles, an image receiving element arranged to receive the projected image of the neck area and having a plurality of electrooptical elements, wherein the projecting element includes a mirror arranged to project the image of the neck area of each of the articles along a projecting axis which is transverse to the longitudinal axis of the device, and the electrooptical elements are arranged in a circle located in a plane normal to the projecting axis.

Abstract: The apparatus includes a photoelectric sensor associated with a predetermined zone of a hollow glass article to be examined for faults. During one testing operation, the photoelectric sensor successively detects all faults in that zone and generates for each a fault signal whose value is dependent upon the characteristics of the fault. The fault signals are applied to a threshold circuit which generates an output signal only when the fault-signal value exceeds a threshold-signal level. The setting-up procedure involves performing at least one preliminary testing operation upon a preselected sample or standard article having acceptable faults. Each threshold-circuit output signal automatically results in a circuit adjustment which reduces by a predetermined amount the extent to which the respective fault-signal value exceeds the threshold-signal level.