Patent ID: 6876459

Claim:
Apparatus ( 10 ) for locating the leading edge (E) of an object (A) comprising: a first light source (S 1 ) illuminating a portion of the object including its leading edge; a first imaging means (M 1 ) obtaining an image of the portion of the object illuminated by the first light source; a second light source (S 2 ) spaced apart from the first light source and also illuminating a portion of the object including its leading edge; a second imaging means (M 2 ) spaced apart from the first imaging means and obtaining an image of a portion of the object including its leading edge; and, processing means (P) processing the respective images obtained by the first and second imaging means to reconstruct the leading edge of the object and establish its location, wherein the position of the first light source (S 1 ) and the second imaging means (M 2 ) are co-located in space so to be coincident with each other as is the position of the second light source (S 2 ) and the first imaging means (M 1 ), thereby for the processing means (P) to utilize similarities in illumination of the object by the respective light sources and regions of mutual illumination and observation of the object to reconstruct the leading edge (E) of the object (A).