U.S. International Trade Commission has launched a patent infringement investigation of certain Nikon digital cameras, software and components

      

Reuters reports that the U.S. International Trade Commission has launched a patent infringement investigation of certain Nikon digital cameras, software and components triggered by a complaint from Carl Zeiss and ASML.

Everything started last month when Nikon filed a lawsuit against ASML and Carl Zeiss over patented semiconductor lithography technology. Three days later Zeiss and ASML started suing Nikon back

I am not a lawyer, but it is way too early to speculate what the outcome of all this will be. Cases like this usually take years and end up being settled out of court. My only issue is if Zeiss and ASML had a valid reason to sue Nikon, why did they wait until Nikon filed a lawsuit against them?