After installing the the nvidia graphic drivers for Ubuntu 14.04, an Nvidia splash would keep appearing during logon.
One command to disable Nvidia logo
Refer: http://ubuntuhandbook.org/index.php/2013/08/remove-nvidia-logo-from-ubuntu-startup-screen/
The easiest way to do this is running below command in terminal (press Ctrl+Alt+T):
$ sudo nvidia-xconfig --no-logo