Helicopter pilot experienced a NMAC with an R22 shortly after liftoff from a refueling helipad.

Narrative

I was leaving our refuel helipad to pick up my crew. I was taking off into the wind toward the JWN Airport and conducting a right climbing turn. At approximately 80 FT AGL; out of the corner of my eye; I noticed a light blue R-22 helicopter approximately 30-40 FT above the trees directly below me and approximately 40-50 FT away. The R-22 was to my right rear where I could not see it. I did not hear them call out base to final and had asked my company aircraft; who was there with me at the refuel helipad if he had heard a radio call from that aircraft. He said he only heard the radio call from crosswind to downwind. I asked the Robinson pilot if he saw me and he said that he had me in sight the whole time. Why didn't he let me know on the radio where he was? This is not the first time I have noticed the R-22 on that same pattern and at that same low altitude. The refuel pad for our company is very busy at all times of the day and night and is located next to the John C. Tune airport. The R-22 was training and I believe was flying a traffic pattern to the taxi way and on the opposite side of fixed wing traffic. Generally; all traffic pattern flight is conducted on the west side of the airport. This incident could have been avoided had the 'flight training' been conducted on the west side in the normal traffic pattern or at standard traffic pattern altitude. In the future; I will also be more diligent in scanning the airspace above and listening for radio traffic.