If you don’t use the phone for a while, the screen and backlight will turn off to conserve battery power. To unlock the phone:
Press the Power/Lock Key . Your Lock screen will appear.
Swipe the screen in any direction to unlock the default Lock screen. To use a shortcut, swipe the icon in any direction. The screen will unlock and the application will launch.
The default Lock screen simply locks the screen to prevent unintentional actions. For more security to guard against unauthorized use, you can an unlock requirement (such as a pattern, PIN, password, or face recognition) that will need to be entered to unlock it.
Different clock themes can be applied to the lock screen.