Its probably not screen saver.
HAANS.G or should be HANNS.G is a brand of diplay Monitor. It has a feature "Power Saving Mode" or OSD time out. In your case probably OSD is "ON" like if your display is idle for sometime or OSD timer is set, the display will turn off.
Check the LED color if during off display there is like orange LED blinking (in some model). You can turn OFF the OSD in the front panel of the Monitor, panel location depends on the Model.