If you don’t use the tablet for a while, the screen and backlight will turn off to conserve battery power. To unlock the tablet:
The default Lock screen simply locks the screen to prevent unintentional actions. For more security to guard against unauthorized use, you can set an unlock requirement (such as a pattern, PIN, password, or face recognition) that will need to be entered to unlock it. Please refer Using a Screen Lock on page 23 for more information.
Turn the screen on.
Press the Power/Lock Key on the right side of
the tablet.
OR
Quickly double-tap the center of the screen (KnockON).
The default Lock screen will appear. From the center of the screen, swipe in any direction to unlock it.
To use a Swipe Lock screen shortcut, swipe the shortcut icon at the bottom of the screen in any direction. The screen will unlock and launch the app.