Transparent container sidewall thickness measurement with a line-shaped light beam

摘要

Measuring wall thickness of a container (32) includes a conveyor for moving the container transversely of its axis through an inspection station and simultaneously rotating the container about its axis. A light source (34) and an illumination lens system (36) direct onto the wall of the container a line-shaped light beam (35) having a long dimension perpendicular to the axis of the container and parallel to the direction of movement of the container through the inspection station. A light sensor (48) (linear array) and an imaging lens system (46) direct onto the sensor light energy reflected from portions of the outer and inner sidewall surfaces that are nearest to the sensor. Cylinder lenses and fresnel lenses are used or a moving mirror is used to produce the line-shaped light beam (35) for having a reduced sensitivity to container position. Also not only a single but several containers can be measured at one time. <IMAGE>