Apparatus and a method for illuminating a light-sensitive medium

A system for illumination of a light sensitive medium comprising:

• means for patterning each of a plurality of beams using an illumination unit comprising at least one illumination head, the illumination head comprising at least two arrays of individually controllable light valves;
• means for projecting the patterned beams onto the light sensitive medium;
• and
• means for displacing the light sensitive medium relative to the patterned beams, such that the patterned beams are scanned across the light sensitive medium in a scanning direction;
• and
• means for directing the patterned beams towards the light sensitive medium by means of lenses arranged such that each lens directs a respective part of a respective patterned beam towards a respective target area on the light sensitive medium,
• means for spacing said arrays apart in the scanning direction, such that each of the arrays scans the patterned beams across the areas of the light sensitive medium as the light sensitive medium and the at least one illumination head are displaced relative to each other, the respective target areas scanned by the patterned beams are contiguous;
• and
• means for individually controlling the individually controlled light valves of said illumination unit in dependency of the relative movement between the illumination head and the light sensitive medium.

A method for point illumination of a light sensitive medium, comprising forming patterned beams by at least two arrays of individually controllable light valves onto a light sensitive medium;

• and
• displacing the light sensitive medium and the patterned beams relatively, such that the patterned beams are scanned across the light sensitive medium in a scanning direction;
• and
• individually controlling the light valves of said individually controlled light valves in dependency of the relative movement between the illumination head and the light sensitive medium;
• and
• positioning the at least two arrays of individually controllable light valves on the illumination head relative to each other, such that the arrays are mutually displaced on the illumination head and such that the respective target areas scanned by the patterned beams are contiguous.