SD cards and Flash drive for ipad

I put a root folder named DCIM (as suggested by a person on here) on a flash drive and an SD card so I can try and put pics on it from a PC to view on iPad It did not work . I took out the memory card from my camera and it picks up all pics taken from that camera,if I transfer pics to that SD card they will not show ??? Can anybody help

This question is also answered in the other thread, but just in case someone else stumbles across this one.

The images inside the DCIM folder have to have the following name structure: IMG_xxxx.jpg
where xxxx are any digits, I.e. 1234