| 摘要 |
A method for contour recognition of completely or partly transparent objects (2), e.g. containers like glass or plastic bottles, the object being advanced through an illumination and detector station (3-13; 3, 4, 20, 21) and there being illuminated on at least part of its circumference. The light reflected by the object (2) is viewed by a detector (4,3) against a background that is dark relative to the object, and the viewed image is recorded and converted to pulse signals that are processed to yield a numerical code characteristic of the object. During recording distinct signals are generated which are characteristic of the width (bn) of the object relative its corresponding height (hn) for a number of levels (n). The signals are then processed in a threshold circuit (24) and a pulse generating circuit (25) for the generation of the pulse signals (P), for each height (hn) two pulses (22', 23') being formed, the distance between the leading edge of the first pulse (22') and the trailing edge of the second pulse (23' ) defining the width (bn) of the object at said height (hn). The distinctive signals are preferably generated by a TV camera, e.g. a CCD camera. Utilization especially in connection with contour recognition of return bottles. |
