Verfahren und Vorrichtung zur Pruefung einer Flasche auf Fremdkoerper

1278491 Inspecting bottles for blemishes photo-electrically MITSUBISHI JUKOGYO K K 6 Aug 1969 [7 Aug 1968] 39443/69 Heading G1A [Also in Division G2] In a method of testing a bottle, light received within the bottle is divided into a number of separate channels and then converted into separate electrical signals, these signals being amplified and supplied to circuitry including an OR-gate 23 so as to detect the presence or absence of foreign matter on the surface of the bottle. The instrument shown in Fig. 1 is located inside a bottle, and light is deflected by a mirror 7 and focused by a lens 6 on to one end of an optical fibre bundle 4, the other end of the bundle being divided into three separate spaced sections 4a, 4b, 4c. Between each of these sections and its corresponding photoelectric transducer 10a-c is located a glass plate. As shown in Fig. 6, associated with each transducer is an amplifier 20a-c, an integrator 21a-c and a shaping circuit 22a-c. Subsequent to the shaping circuits are an OR gate 23, an AND gate 26 and a memory circuit 27. A branch circuit from transducer 10a to the OR gate contains a D. C. amplifier 24. The second input to the AND gate is connected to a trigger circuit 25, which produces a gating pulse during the inspection period of each bottle. A reset pulse generator 28 is provided for resetting the memory circuit. In use, the bottle is rotated while the inspection device is raised or lowered, to scan the side surface of the bottle in a spiral manner. When a blemish is scanned, at least one of the transducers will produce a pulse which, in modified form, is fed to AND gate 26 to operate a reject mechanism. If the entire surface of the bottle is covered with foreign matter, the transducers detect no change in light level, and hence they produce no reject signal. However, in this case the D. C. amplifier 24 is arranged to provide an output whenever transducer 10a does not produce an output and hence this amplifier generates a reject signal.