How to Change the Windows 10 Lock Screen Timeout
 

By default, Windows 10’s lock screen times out and switches off your monitor after one minute. If you’d like it to stick around longer than that–say, if you have background picture you like looking at or you enjoy having Cortana handy–there’s a simple Registry hack that will add the setting to your power options.

http://www.howtogeek.com/267893/how-...creen-timeout/