PURPOSE: To print a picture clearly by incorporating a printing light source, having a louver partitioned into many prisms arrayed linearly, between two static-electricity generating rolls.

CONSTITUTION: Between static-electricity generating rolls 5 and 6 rolling on a photographic film applied with positive charge in contact, a light source 8 provided with a louver 10 is arranged. This louver 10 has a prismic partition space 12 formed by many partitioning plates 11 arrayed linearly. Consequently, light differing in angle of projection is prevented from reaching an unexposed film superposed upon a negative film, and a picture is printed clearly.