1920x1080 doesn't completely fill the screen?

Hi,

The title of this thread makes a lot clear about my problem I guess.
I use a Philips tv in combination with a ASrock E350M1/USB3 motherboard.
The screen resolution is set to 1920x1080 (16:9) but it still shows black edges at the sides.

No I don't mean the usual black bars at the bottom and top.
This is at all sides of the screen!

I temporarily solved this by opening catalyst control center and set the bar about over- and underscan to position 8. (catalyst control center -> selected my screen -> adjustments at the top -> options screen size)
Please excuse me for my English. I have a Dutch installation so my translations may differ a bit from English installations.

So at this moment it is screen filling but as you probably can understand it's not how I want it to function.
Anyone has an idea how to fix this?

Thanks in advance!