@Moroboshisan: I've attached one schematic here for you, I did it myself for one project that I did for my college. Not sure how much simple you need it to be but I consider this one very simple

The advantage of this circuit is that it doesn't suffer from another kind of IR interference (like solar or lamps) and have a range of around 3 meters if well positioned when detecting reflected signals.
You can easily adapt to your Arduino processor to check 0VCC / 5VCC, the PHSC38 sensor will switch it's output terminal to 0VCC when it receives a 38khz IR modulated signal.