B767 First Officer reported loss of all route data from both FMC's during or shortly after takeoff from ORD. Vectors were requested until data could be restored.

Narrative

After takeoff from Runway 14L in ORD; we climbed to 5000 FT and were on an assigned heading when Departure issued a clearance to MOBLE; which was the first point in our route. The Captain turned the heading selector to where he thought MOBLE was and tried to select direct MOBLE on the left FMC. I looked at my display and saw nothing; no route; no points; nothing but a triangle on the screen. We had been given a reroute from clearance delivery of MOBLE; ADIME; IDEAS; as filed and had changed and double checked the new clearance. I looked at the FMC and Route 1 in the FMC was empty; no route; blank legs page; and VNAV would not engage. While the Captain tried to put something in the route; departure asked if we were going direct to MOBLE; and I asked for a heading until we could get the FMS working. Departure gave a turn of about 20 degrees to the right. The O'Hare 3 departure; shows some of the initial fixes with radial and DME; but most do not and have only latitude and longitude. MOBLE is shown only as a point; no radial/DME. It would be helpful to have radial and DME off ORD for all of the initial fixes on the departure available somewhere; because aside from a heading from departure; there is no way to find MOBLE.