In Windows 8.0 there was an option in "Change PC settings" (the metro-style modern mode settings) to lock the screen after the screen has been off a certain amount of time. If you turn the screen on before the time expires, you could simply swipe up without requiring a password.
But now in Windows 8.1 (6.3, Build 9600) I can't find this feature. How do you do this in Windows 8.1?
I've seen that changing the power settings to "Balanced" has pseudo-enabled this functionality. The screen turns off, and turning it back on does not require a password until some further time after the screen has been off. I believe this is because the screen timeout is sooner than the sleep timeout, and so the password is required after sleeping only.
My ideal functionality would be that a password is not required until some specified timeout even if the machine has gone to sleep. This would make the power button tons more useful.