From a Home screen, navigate: Apps icon > Settings > Display.
Tap Sleep then select an option (e.g., 15 seconds, 30 seconds, 1 minute, etc.).
To control what happens when the phone is docked or charging:
Tap Screen saver.
Tap the Screen saver switch to turn on or off .
Select a setting (e.g., Clock, Colors, etc.).
Tap the Back icon (upper-left) to return to the display settings screen.
Tap Display size then select how large or small to make items appear on your screen.
To select a size, touch and hold the blue dot then drag left or right to the desired option (e.g., Default, Small, Large, etc.).
Tap the Back icon to return to the display settings screen.
Tap Auto-rotation turn on or off .
On allows the screen to go into landscape mode when turned on its side.