Patent ID: 7433255

Claim:
System comprising: an optical element ( 102 ) for generating a periodic array of light spots ( 103 ) intended to be applied to an information carrier ( 101 ), said information carrier ( 101 ) comprising a first periodic structure ( 108 ) intended to interfere with said periodic array of light spots ( 103 ) for generating a first Moiré pattern, and a second periodic structure ( 109 ) intended to interfere with said periodic array of light spots ( 103 ) for generating a second Moiré pattern, analysis means for deriving from said first and second Moiré patterns the angle value (δ) between said periodic array of light spots ( 103 ) and said information carrier ( 101 ), actuation means (AC 1 -AC 2 -AC 3 ) for adjusting the angular position of said information carrier ( 101 ) with respect to said array of light spots ( 103 ) based on control signals ( 114 ) derived from said angle value (δ).