Image acquisition system for parcel sorting

摘要

The system comprises a high resolution camera (1) mounted above a conveyor belt (4) on which objects are placed, with their sides to be examined uppermost. The camera is fitted with an objective lens (5) with a motorised focussing mechanism operating with a sensor (8) which produces a signal representative of the height profile of the upper face of each object w.r.t. the conveyor plane. This profile signal serves to produce reference positions (C) for the focussing system, taking account of variations in the height of the upper surface of each object as it passes in front of the camera. The sensor used may be a telemetry laser, whilst the camera may be a CCD device and the motorised control operated by a DC electric motor.