LIGHTING SYSTEM FOR CONTRASTING ENGRAVED CODES

摘要

The invention relates to a lighting device for increasing the contrast of an image of a concave or convex structure provided on a surface (S), said device comprising: a first light source (44i) arranged so as to emit, according to a first axis of incidence Ii, a first light, the bandwidth of said first light, or "first bandwidth", being less than 100 nm; a second light source (442) arranged so as to emit, according to a second axis of incidence I2, a second light, the bandwidth of said second light, or "second bandwidth", being less than 100 nm; and a third light source (56) arranged so as to emit, according to a third axis of incidence I3, a third light, the bandwidth of said third light, or "third bandwidth", being less than 100 nm, the first, second, and third axes of incidence being substantially convergent and the bandwidths of the first, second, and third lights being divergent from each other.