LED illumination source

A LED illumination source comprising:

• one or a plurality of LED illumination modules, each LED illumination module comprising a plurality of LED clusters, wherein groups of LEDs of the plurality of LED clusters are electrically linked in current chains, wherein LEDs in each of the groups of LEDs are electrically linked along a line which is diagonal to a direction of sweep, wherein the LED clusters are rotated by an angle of rotation with respect to an axis which is parallel to the direction of sweep, wherein the angle of rotation is determined as a function of k, where k is a number of LEDs in a row of any of the LED clusters.

An inkjet printer comprising:

• at least one printhead to deposit droplets of ink in a predetermined pattern on a substrate;
• and
• an LED module to generate curing radiation onto the substrate after the ink pattern is deposited onto the substrate, wherein the LED module comprises a plurality of LED clusters, wherein each LED cluster comprises a LED array which is rotated by an angle of rotation with respect to an axis which is parallel to a predefined direction of sweep of the LED module with respect to a direction of travel of the substrate on which the ink pattern is deposited, wherein the angle of rotation is determined as a function of k, where k is a number of LEDs in a row of any of the LED clusters.