In the past, I have filed patent infringement lawsuits on the same day that the patent issued. That highly aggressive strategy is not the only approach — many patentees delay years before filing suit.
In order to determine how long patentees usually delay before filing suit, I pulled-up all twenty-one hundred US patents that have been asserted in patent litigation or reexamination cases in 2007. (Restricted to lawsuits filed 1/1/2007 to 8/15/2007 notice of litigation had been filed with the USPTO).
For cases filed in year 2007, the ‘average’ patent issued seven years ago in 2000. The median issue year was 2001 — a six year delay in filing. The histogram below provides an idea of the distribution of the number of years between patent issuance and commencement of litigation for the 2007 lawsuits.
Although most lawsuits are filed by the time a patent is six years old, it is striking that about twenty-five percent of the patents in the 2007 lawsuits are more than a decade old.