▁history ▁of ▁Arizona ▁Category : Sil ver ▁mines ▁in ▁Mexico ▁Category : 1 7 3 6 ▁establish ments ▁in ▁North ▁America <0x0A> </s> ▁Net ac ▁Technology ▁Co ▁Ltd ▁() ▁is ▁a ▁consumer ▁electron ics ▁company ▁based ▁in ▁Sh enz hen , ▁China . ▁A ▁Chinese ▁O EM ▁and ▁O DM , ▁the ▁company ▁claims ▁to ▁have ▁invent ed ▁the ▁USB ▁flash ▁drive . ▁ ▁History ▁ ▁F ounded ▁on ▁ 2 9 ▁April ▁ 1 9 9 9 ▁by ▁Gu osh un ▁Frank ▁D eng ▁and ▁Ch eng ▁X ia oh ua , ▁the ▁two ▁worked ▁for ▁a ▁year ▁developing ▁their ▁first ▁product , ▁an ▁eight ▁meg aby te ▁flash ▁memory ▁drive ▁that ▁D eng ▁christ ened ▁the ▁U ▁disk . ▁ ▁Flash ▁drive ▁ ▁On ▁July ▁ 2 4 , ▁ 2 0 0 2 ▁Net ac ▁was ▁granted ▁its ▁first ▁pat ent , ▁for ▁an ▁electronic ▁flash ▁memory ▁external ▁storage ▁method ▁and ▁device . ▁At ▁least ▁ 1 4 ▁companies ▁have ▁since ▁requested ▁invalid ation ▁of ▁this ▁pat ent , ▁as ▁"[ the ▁pat ented ▁device ] ▁has ▁been ▁anticip ated ▁by ▁the ▁combination ▁of ▁two ▁references , ▁i . e . ▁USB ▁System ▁Architecture ▁and ▁the ▁Hand book ▁of ▁Flash ▁Memory ▁Technology ▁published ▁in ▁ 1 9 9 7 ▁and ▁such ▁combination ▁is ▁obvious ▁to ▁those ▁sk illed ▁in ▁the ▁art ." ▁ ▁Although ▁the ▁company ▁claims ▁to ▁have ▁invent ed ▁the ▁first ▁USB ▁flash ▁drive ▁in ▁ 1 9 9 9 ▁and ▁submitted ▁a ▁Chinese ▁pat ent ▁application ▁for