Here’s a quick tip that shows you how to disable screen black out in Ubuntu 12.10. When you install Ubuntu, by default the screen times out and turns dark every 10 minutes when inactive.
This brief tutorial will show you how to turn off that feature so that your screen never goes to sleep or blank. It will stay on continuously even when not in use.
To get started, go to Ubuntu Control from the top right corner and select ‘System Settings..’
Then select ‘Brightness and Lock’
Finally, choose Never so that the screen never turn off.
The image above also shows you how to disable the screensaver lock (lock screen) and how to make sure Ubuntu doesn’t ask for password everytime you want to resume from a lock screen.