Android Question keepalive i'm becoming crazy

Hi

it seams a stupid question but i can't find the way to solve it .

I need to light the screen from code and let the SO to dimming and power off the screen .

You can say : use keepalive(false) , but no !!

If i use keepalive(false) the screen is lighted but remaing on , and if i after call releasekeepalive the screen go off immediataly without the SO dimming time,

Can you help me ?

Thanks