the IR modules are 3 lead sensors , which have biult in PLL,LPF, etc.
the PLL will lock on at 38Khz ,and combined, the o/p will be high/low signal for No IR and IR conditions.
so generate a 38Khz wave using 555 , have a digital modulation by applying suitable pulses to the reset pin of 555 Txmit the o/p with a driver transistor+IR Led (for increased range), u'll get the inverse of that at the o/p of the IR sensor.
sorry i don't have a dia right now