Locking And Unlocking Your Device - Samsung GALAXY S4 Quick Reference Manual

LOCKING AND UNLOCKING YOUR DEVICE

By default, the device screen locks when the backlight turns off.
To unlock your device from the lock screen:
X With your device turned on, press
to wake the display and sliding your finger across the
screen in any direction.
To lock your device screen:
X Press
8
(Power/Lock). The screen goes black.
(Power/Lock)