Nokia Lumia Icon: Get started
Lock screen
Want to avoid accidentally making a call when your phone is in your
pocket or bag?
Press the Power/Lock Key.
Chapter 1
Unlock the screen
Press the Power/Lock Key, and drag the lock screen up.
Screen timeout
From the Start screen, swipe left, tap
Screen times out after, and select the length of time after which the
keys and screen are locked automatically.
Settings > lock screen >
12