in my previous entry, i posed an idea how to use the built-in proximity sensor to turn the screen off and locked. hereinafter i will show you how to use it vice versa.
Profile: (proximiy screen on)
context1:state-sensor-not proximity sensor,
context 2:state-display-display off
action: (Android 4.0+) display-turn on, if available (Android 2.3-)plugin-secure settings,configuration -wake device
if you want your phone keyguard off while the screen turns on, use display, keyguard off action, please.
NB. please make sure in tasker preference interface, you have set the proximity sensor option to "Yes", so that, the proximity sensor would stay active after the screen turns off by default.