From looking at the image, it would appear that you are printing on roll paper that has an excessive initial curl. Set the roll paper options in the print driver to wider. This should take care of the head strike problem.
You can also clean the bottom of the print heads carriage by placing a cut paper towel that will fit into the carriage pathway. Saturate the paper towel with a little Windex and and warm water. With the machine powered down and the head released, slowly slide the print head back and forth over the wet paper towel a few times. This should clear any excessive ink build-up on the bottom of the print head. Repark the head, remove the dirty paper towel and make sure there are no lint particles or dirt left behind in the carriage pathway.
Gene