In a fiber optic development kit, the schematic for the input to drive the LED is a bit puzzling to me. What is the purpose of the arrangement of inverters after the input? U1 is a 4069 and Q1 is a 3904.
http://i55.tinypic.com/2u44pax.jpg

 

Hi Razor Concepts,

The device driving the input cannot drive the transistor directly so the the circuit designer added two CMOS logic inverters in parallel to get enough drive for the transistor. The buffer next to the input un-inverts the signal and presents only one CMOS load to the device driving the input.

Regards,
Ifixit