5. Dynamic tomographic lighting

Dynamic sheets are obtained by scanning a focused laser beam through a rotating or oscillating reflector. The use of rotating mirrors is the simplest and least expensive method, but offers little flexibility if scanning parameters (mean position and amplitude) are to be changed frequently. It is also limited to the production of flat sheets. Oscillating reflectors are generally set in motion by servo-controlled ferromagnetic galvanometers: their field of application is wider because of the ease of electrical adjustment of the web's geometric parameters, the diversity of control signals (shape and frequency) (figure 8 ) and the possibility of generating three-dimensional webs, by combining a double xy deflector; on the other hand, the current frequencies of these systems are limited to a few hundred...