Submarine patents

A submarine patent is a patent published long after the original application was filed. Like a submarine, it stays under water, i.e. unpublished, for long, then emerges, i.e. is granted and published, and surprises the whole market. This practice is now only possible under the US patent law, and to a very limited extent since the US signed WTO's TRIPs agreements, making compulsory the publication of patent applications 18 months after their filing or priority date. Submarine patents are considered by many as a procedural latch.

Mechanism

In the past, i.e. before US patent applications were automatically published 18 months after their filing or priority date, an applicant for a US patent could delay the grant of the patent by filing a succession of continuation applications. Some submarine patents emerged some 40 years after the date of filing of the corresponding application.

Currently, all US patent applications are published 18 months after the filing date except for US patent applications for which the applicant explicitly certifies at the filing date that he will not file corresponding patent outside the US (in a recent report though the National Academy of Sciences has recommended that "in all cases, applications should be published during patent examinations" ).

Famous submarine patent owners

Jerome H. Lemelson filed a lot of applications that became submarine patents. He and his heirs have collected over 1.3 billion dollars (U.S.) in royalties. Many of these patents, covering machine vision and bar codes, were struck down in January 2004 by the federal district court in Las Vegas, Nevada: "At a minimum, Lemelson's delay in securing the asserted claims amounts to culpable neglect as he ignored the duty to claim his invention properly.... If the defense of prosecution laches does not apply under the totality of circumstances presented here, the Court can envision very few circumstances under which it could.... In sum, Lemelson's delay in securing the asserted patent claims is unexplained and unreasonable."