Opto Isolator Switching

I have isolated my limit switches using a TLP540 Opto Isolator,
however it appears unable to drive TTL logic directly and it cannot
switch the input of a 7408 NAND Gate without using a 2N2222
Transistor in between.

Does anyone know if I can drive a ULN2003 Darlington directly from
the isolator without having to use the 2222 as an amplifier ??

I am also experiencing some switch bounce and wondered if it would
be preferable to setup an R/C network to turn the signal into a
pulse or to dampen the switching ??

Thanx

PeterC