2007 Patent Litigation: Timing the Transition from Patent Issuance to Patent Litigation

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.


6 thoughts on “2007 Patent Litigation: Timing the Transition from Patent Issuance to Patent Litigation

  1. 6

    regarding timelines,
    At what point does each side realize their respective weakness-strengths? Is there any connection to an overwhelming favorable claims construction and to the decision to settle?

  2. 5

    Dennis, how do you pull up the data on which patents are litigated? I was not aware of any list or database that has this information.


  3. 4

    I would certainly be interested in seeing how the timetables relate to different technologies.

    Six or seven years may be two or three generations in a dynamic computer/electronic field, whereas pharmaceutical developments take very much longer.

    On the other hand, it is very much easier to monitor for infringment of pharma patents.

    In some fields, any product will almost certainly infringe something, and the more complicated the product, the more likely that is to be the case, e.g. mobile phones etc. Here, the patentee will be more keen in licensing as the fields are competitive and blocking will not neccessarily increase market share. In drug cases, that is obviously not the case.

    The time lag between filing and bringing a product to market and the likelihood of patents being maintained in the fields should be compared with the timescale for filing infringment claims.

    If you compare with trademark developments, many marks die a natural death fairly quickly as the companies go out of business. The exceptional marks are being defended in court maybe 100 years after filing, see Levi stitching, Red Cross, etc.

  4. 3


    another factor to consider is whether drug patents skew the results. Under Hatch-Waxman, a generic version of a new drug (i.e., a NCE) can’t enter the market until five years after approval. Five years after first approval is often more than five years after the issuance of the first patent covering the drug. (Other periods apply to different approvals.)

    You should consider parsing the results based on whether it was an ANDA filing or not. I suspect that ANDA filings skew the results to longer delay before filing.

  5. 2

    It bears pointing out that the results of your research mesh nicely with the 6 year statute of limitations unsder Section 286. It makes sense for people to sue after 6 years (especially non-practicing inventors) in order to get the most bang for their buck. I believe this will become even more evident in the post-eBay era where injunctive relief has become significantly harder to get.

  6. 1

    The one bit of information that is missing that would breath life into your analysis is when did the patent owner discover the infringement. Claiming that the chart provides information on delays in suing is based on the assumption that all the patent owners knew of the infringement at the time of issuance, since that is your starting point. My experience tells me that this is a false assumption.

    But, your chart does provide support for the supposition that patents have value later in their life. The time between patent issue to the time of enforcement litigation gives information on how valuable patents are towards the end of their life, and I think 25% of the patents being enforced 10 years after issuance is significant.

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