Auto screen dimming issue, not the sensor

I have the iPad mini running OS 6.0.2. Liking it so far unless reading a kindle book (but have replicated the issue in other apps as well). After a minute or two, I have the font small and view horizontally so it can take longer to get though a page, the screen automatically dims. I didn't experience this with my old iPad 1, (which the mini just replaced) or my wife's iPad 2 with OS 6.0.2.

I understand this is an energy management feature, but I want to turn it off. Setting the Auto Adjust Brightness to OFF does nothing, and my fingers are no where near the sensor anyway. Not experiencing the other brightness issues others seem to be having. I tried the manual and searching discussions/support articles, and no dice, zip, nada. So I'm not sure if this is something that can even be done. Any ideas?