Patent Law

This is Part II of my series on the relevance of the invention date in patent prosecution. You may download my entire paper here.

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Using the USPTO PAIR electronic database, I obtained biographical data for 21,000+ randomly selected patent applications filed between 2000 and 2007. The biographical data includes a listing of affidavit filings. After obtaining PDF versions of the affidavits, we categorized them by hand to identify those affidavits associated with an applicant asserting rights based on the invention date. These were typically Rule 131 affidavits.

Of the 21,000+ application file histories in the data set, 0.7% (138) included a Rule 131 affidavit asserting invention-date based novelty rights. However, only 0.1% of the applications included a Rule 131 affidavit that led directly to an issued patent without further substantive action. Interestingly, antedating was not even necessary in some of those successful cases. For instance, several of those applicants had received patents in Europe without relying upon any invention-date-based priority.

One of the most oft-cited advantages of the U.S. invention-date focus is the relative benefit it brings to individual inventors, new entrant small companies, and universities. If these groups are disproportionately benefiting from the U.S. system, we would expect to them taking advantage of their invention-date-based rights. To test this hypothesis, I obtained assignment information (if any) for each application in my Rule 131 affidavit sample, and classified each assignee according to its size and type.

In both absolute and relative terms, companies?especially large and publicly-traded companies?claim invention date rights more often and more successfully than do individual inventors. U.S. publicly-traded companies appear to be disproportionate users of novelty rights: 61% of the applications with Rule 131 affidavits were assigned to these publicly-traded companies. However, the same companies hold only 27% of issued patents. Individual inventor usage of invention-date-based novelty rights did not differ significantly from that expected: the proportion of applications with Rule 131 affidavits that were filed by individual inventor-owners closely resembled the proportion of inventor-owners in the general population of patentees. Meanwhile, the percentage of applications with Rule 131 affidavits that were filed by universities essentially doubled the share expected given the ordinary frequency of university-owned patents. The clearly underrepresented group is that of foreign companies whose applications only represent 10% of those asserting novelty rights but occupy almost half of the general population of patents. As measured by allowance rate, companies tend to have a much more success than individual inventors in obtaining patent protection through the assertion of their invention dates in Rule 131 affidavits.