If you encounter a poor printing quality, there are several things that you can do to improve that. Make sure that you are using a quality paper. It's possible, that this might cause the problem. Try to download and install the latest version of the driver, and make sure that you are using an official program for printing. You can access the download section on the official support website for all the available downloads.
If none of the mentioned solutions didn't solve the problem, try to contact an official service, because your problem could be caused by a hardware malfunction and it isn't advised to troubleshoot it by yourself.