Patent ID: 6275603
Filing Date: 2001-08-14
Classification: G01N

Abstract:
Method of detecting the presence of glass particles in a bottle filled with a beverage, the bottle (1) having a bottom (4) with a central, inwardly directed convex portion (6), and also having a longitudinal axis (13); the method comprising the steps of:a) causing the beverage (10) in the bottle (1) to rotate with respect to the bottle (1);b) holding the bottle (1) stationary with respect to a camera (40);c) illuminating the bottle (1) with a light bundle (31) impinging on the bottom (4) of the bottle (1), said light bundle (31) being directed substantially parallel to said longitudinal axis (13) of the bottle (1);d) directing the camera (40) such that an optical axis (41) of the camera (40) makes an angle .alpha. in the range of 120.degree.-150.degree. with the direction (32) of the bundle (31);e) obtaining a first image signal representative for a first image obtained by the camera (40) at a time t.sub.1 when a present glass particle is in a first position and a first orientation within said bottle;f) obtaining a second image signal representative for a second image obtained by the camera (40), the second image being obtained at a moment in time t.sub.2 subsequent the moment in time t.sub.1, said glass particle being in a second position and a second orientation within said bottle;g) comparing the first and second image signals to obtain a first compared signal;h) obtaining a third image signal representative for a third image obtained by the camera (40) at a moment in time t.sub.3 subsequent the moment in time t.sub.2, said glass particle being in a third position and a third orientation within said bottle;i) obtaining a fourth image signal representative for a fourth image obtained by the camera (40) at a moment in time t.sub.4 subsequent the moment in time t.sub.3, said glass particle being in a fourth Position and a fourth orientation within said bottle;j) comparing the third and fourth image signals to obtain a second compared signal;k) generating a bottle reject signal if at least one of the compared signals obtained in step (g) or step (j) indicates the presence of a moving object.