| 摘要 |
<p>A foreign object separation apparatus comprises a feed conveyor (8) for delivering material to be processed to an inspection region where the material descends, means (10, 11) for illuminating the material in the inspection region, a plurality of fluid blast nozzles (22), a plurality of solenoid controlled valves (21) connected respectively to said nozzles, a camera (12) for scanning the material descending in the inspection region, a background compensation and video comparator (23) connected to said camera to receive pixel data therefrom, and a reject position decoder (18) for receiving reject data from the comparator, a programmable zone boundary decoder (19), the outputs of said reject position decoder (18) and said boundary decoder (19) being synchronized by clock signals outputted by said camera, and a zone decoder logic circuit (20) connected to the outputs of said reject position decoder (18) and said boundary decoder to produce output signals which actuate said solenoid controlled valves. The said zone decoder logic circuit (20) is programmable so that when a reject data signal from said comparator (23) representing a position falling wholly within a main zone (1-8) but outside an overlap zone (9-15) is decoded in the zone decoder logic circuit, the corresponding valve only will be actuated, whereas when a reject data signal from said comparator representing a position falling wholly or partly within a main zone, and also wholly or partly within an overlap zone is decoded in the zone decoder logic, the valves (21) controlling the nozzles (22) or groups of nozzles on each side of the reject position will be actuated.</p> |
