The present invention relates to an active alignment method of a receiving device (2, 2′) including a sensor (4) and of a illumination device (6, 6′) including at least one light source (18, 8′) suitable for emitting a beam of light, including: —Assembling said receiving device (2, 2′); —Stably fixing said receiving device (2, 2′) on a chassis (30); —Actively aligning an optical group (11, 11′) of said illumination device (6, 6′) with respect to said light source (18, 18′); —Fixedly connecting said optical group (11, 11′) of said illumination device to said light source (18, 18′); —Actively aligning said illumination device (6, 6′) with respect to said receiving device (2, 2′); and —Stably fixing said illumination device (6, 6′) to said chassis (30).