A Proposal for Limiting Patent Continuations

In "Ending Abuse of Patent Continuations," MARK A. LEMLEY of Stanford Law School and KIMBERLY A. MOORE of George Mason University School of Law discuss five alternatives to abolishing patent continuation applications, including

1. Limiting the Number of Continuations
2. Preventing Broadening of Claims During Continuation Applications
3. Improvements to Publishing Applications
4. Intervening Rights
5. Limiting the Time an Application Can Spend in Prosecution

With regard to the fifth alternative, they conclude that their empirical data can provide litigants and judges with a baseline for assessing the reasonableness of delay caused by the filing of multiple continuations by the patentee in determining the applicability of equitable remedies such as prosecution laches:

We suggest that any patent pending six years or longer ought to automatically be subject to scrutiny for laches – a presumption of laches. Six years is more than two standard deviations from the mean of 2.47 years. Although there is some variation by technology in the mean amount of time an application spends in prosecution, that variation is not substantial and would not be significant if a six year presumption were created. For example, measuring the time from the most recent filing date to issuance date of the patents issued in each technological class,192 the technology class with the shortest mean 1.53 years was class 150 Purses, Wallets and Protective Covers and the technology class with the longest application time of 3.18 years was 380 Cryptography. The difference in prosecution time may be somewhat related to the complexity of the technology, but in the case of cryptography many of the patents that issued in this class were delayed because of secrecy orders related to national security issues. Having reviewed the data on each technology class, we conclude that while there is variation by class, the six year presumption is fair to all classes and absent other factors, difference in technology do not justify different presumptive laches periods.

. . . Of course, like litigation laches, the prosecution laches presumption ought to be rebuttable. If the patentee can demonstrate that the delay was not unreasonable but instead there was a legitimate reason why prosecution took so long, then it ought to be able to overcome the presumption. We can think of several reasons that ought to
rebut the presumption: (1) delay caused by an appeal to the Board, the district court, or the Federal Circuit; (2) delay caused by an interference; (3) delay caused by PTO error, or (4) delay caused by a secrecy order that prohibited the patent from issuing.