Hi,
It looks like each segment of the display you're using has 10 LED's. The 74ls47 can only sink 24mA per segment. This will result in a very dim display (2.4mA per LED), or a burnt out BCD driver.
Furthermore, I dont know how many digits you have, but even if you have only ONE digit with all segments decently lighted, that will require about 1.4 amps, which is going to turn your LM317 into a space heater. [20mA x 10LEDs/seg x 7seg = 1.4A]
How about using transistors between the chip and the display?