Disable the "auto-fade after not using iPhone 4 for a few minutes" ??

So sometimes I'll be on my phone and will be reading an article. It may take a few minutes for me to read the entire portion that is shown on my iPhone....so my iPhone will automatically fade or dim if I don't click on anything for a few minutes.

If you're not sure what I mean by the fade thing:

It's as if I clicked the lock button (top right button, next to the earphone jack). Once the phone fades...I'll have to click the home button or the lock button to get to the locked-screen (the screen where you have to slide the bar over to unlock the phone).

Is it possible to disable this function?

PS: I did a bit of searching but was unable to find the answer or someone else with a similar problem (as I would assume most people dont mind this battery-savage feature).

Thanks!

(I'm not positive which iOS I'm running. It's between 4 and 4.2 though.)