Method and apparatus for optically inspecting the profile of containers, the profile including the bottom

An installation including at least one optical inspection station (2) for inspecting containers (3), the station including at least one light source (14) and at least one light sensor (15), the installation including a support table (7) for the containers, which table presents a slide plate (8) on which the bottom of a container stands while it is being inspected by said station while it is positioned between the light source and the light sensor, the installation including a movement system (9) for moving the containers and serving firstly to position the containers in succession on the slide plate while the inspection operation is taking place, and secondly to transfer them successively from the inspection station after the inspection operation, the installation being characterized in that the slide plate (8) includes at least one retractable movable portion (18) lying between stationary portions (21) of the slide plate, the movable portion (18) being movable under the action of an actuator (19) for moving the movable portion (18) between a transfer position in which the movable portion is flush with the table and an inspection position in which the movable portion (18) is lowered relative to the stationary portions such that a portion of the bottom (4) of the container is spaced apart from the slide plate (8), and in that the light source (14) and the light sensor (15) are positioned relative to the movable portion (18) of the slide plate in such a manner that in the inspection position of the movable portion the sensor can receive a light beam emitted by the light source and propagating in an inspection volume (V) in which at least a portion of the bottom (4) of the container is situated spaced apart from the slide plate.