Apparatus and method for simultaneously focusing optical systems according to the diameter of the containers

An installation for observing or illuminating a container section (2) bearing optical singularities on a surface or in a wall, containers each having the container section travelling in translation and each having an axis of revolution (S), the installation including:

• optical systems (6i), each with a work volume located at a work distance and each having an optical path all the way to the container section contained in the work volume of each of the optical systems, the optical systems (6i):
• having, for the containers having a section with a first diameter, respective work volumes thereof each coincident with a part of the container section having the first diameter, each of the work volumes being at a given work distance;
• each optical system possessing an optical path composed of at least one adjustment portion (PR);
• each optical system being translationally guided along a direction parallel to the at least one adjustment portion (PR) of the optical path thereof;
• an optical deflection device (10i) placed on each optical path on each optical system, in such a way that each optical path is divided into at least:
• direct optical paths located in radial planes of the containers, between each container (2) and each optical deflection device (10i), each direct optical path possessing identical angles of observation or illumination of identical values;
• optical fold paths located between the optical deflection devices (10i) and the optical systems (6i) and corresponding to the at least one adjustment portion (PR) of the optical paths;
• and
• at least one driving device (15) providing, when containers each have a section with a second diameter different to the first diameter, movement in synchronous translation of the optical systems (6i) along a direction parallel to the at least one adjustment portion of their respective optical paths and as a function of a difference between the first and the second diameter, the optical systems keeping their invariable respective work distances and their respective work volumes being each coincident with a part of the container section having the second diameter.