After updating to Avast 2015, I noticed that it was constantly scanning (as indicated by the spinning icon in the systray). I found the problem to be the ChiconyOSDService. I determined this by stopping noncritical processes one-by-one with the Windows task manager. I stopped the service and optioned it to start manually–and this stopped the constant scanning.
It seems that you can safely disable the process without causing a problem.
http://en.community.dell.com/support-forums/software-os/f/3524/t/19459459