Auto-Lock
You can set screen timeout by tapping Sleep in Display under 
Settings. If there is no operation within the preset standby time, the display will automatically deactivate, and your IdeaTab will be locked automatically.
Manual Lock
If you do not need to use your IdeaTab temporarily, you can press the Power button for about 1 second to deactivate the display. Your IdeaTab will then be locked, and will enter standby mode.
Screen Unlock
When in standby mode, press the Power button on your IdeaTab to activate the display. Then, tap and hold the lock icon, and drag the slider over the unlock icon, as shown in the illustration below.