Submarine Patents

Article  \  1 May 2008

The problem with submarine patents is that they have been used to generate royalty incomes, by people who have been able to predict developments in a technology, rather than to protect their own developments.


In the US, it has been possible to continuously re-file an application, as a divisional or a continuation, thereby effectively allowing the application to remain pending at the USPTO without going to grant. Before 1995, the patent term of a US Patent was 17 years from the grant of the patent with patent applications not being published until grant.

This system has been used to suppress patent applications, which are then allowed to proceed to grant and receive the 17 year monopoly, at the patentee’s discretion. Such patents have been referred to as “Submarine Patents”.

The problem with Submarine Patents

The problem with submarine patents is that they have been used to generate royalty incomes, by people who have been able to predict developments in a technology, rather than to protect their own developments. For example, an inventor or company may be able to predict the future direction of a particular technology, or the activities of their competitors. In doing so, a patent application could be filed in the US which is not allowed to proceed to grant, but rather is kept pending.

Because there was no pre-grant publication of patent applications in the US before 2000, a third party may then develop a product, which is covered by the scope of the submarine patent, unaware of the pending application. Once the product is on the market, the patent application can then be allowed to proceed to grant. The patentee can then demand a royalty from the unsuspecting third party.

In 1994, the US Congress made moves to prevent submarine patents by amending the patent law so that instead of the term of a patent being 17 years from issue, the term became 20 years from the date of filing. Therefore, if an application is allowed to remain pending at the USPTO, then the applicant is essentially using up their own patent term.

In 1999, Congress took a step further to restrict submarine patents, and from 2000 every US patent application is published 18 months following filing (although there are some exceptions to this automatic publication). It is therefore no longer possible to keep a patent application that is pending at the USPTO secret. There is now a strong incentive for inventors to allow their applications to go to grant sooner, rather than remain pending at the USPTO.

However, there is still some concern that there may still be some submarine patents filed before 1994 that are yet to surface and wreak havoc on potential licensees. However, a recent decision in the US may have finally put the issue of submarine patents to rest.

Symbol Technologies, et. al v Lemelson

Jerome Lemelson was described as a prolific inventor who filed a large number of patent applications, beginning in the 1950’s and continuing through to the 1970’s. Lemelson made few prototypes to confirm his inventions, and he did not directly commercialize any of his inventions. Rather, Lemelson allowed many of his broad technology based patent applications to remain pending at the USPTO, as submarine patents.

Over the years the applications were amended to include supporting data generated from subsequent developments made by others in the field and eventually, when the time was right, the applications were allowed to proceed to grant. Lemelson would then enforce royalty streams from products already on the market. The inventor eventually died in 1997, however, his practices were continued by his company; Lemelson Medical, Education & Research Foundation, Limited Partnership.

At issue in one particular case were a number of Lemelson’s patents that related to machine vision and bar code identification technology. These applications were allowed to proceed to grant in the 80’s and the Lemelson Partnership then demanded significant royalty streams from any products that utilized this technology. While a number of companies agreed to the licenses offered by Lemelson, three companies; Symbol Technologies Inc, Cognex Corporation and Telxon Corporation, counterclaimed against the patents.

Comment by the Judge

In a recent judgment from the US District Court in Las Vegas, the Judge held that the patents were invalid given that the originally claimed system could not be used to read a bar code. Of particular note the Judge also found that it would be inequitable to enforce the patents given the considerable delay, caused by Lemelson’s Partnership, in securing and enforcing the patent rights.

The Judge stated that:

“Lemelson’s delay in securing the asserted patent claims is unexplained and unreasonable. Plaintiff’s ample evidence of intervening rights vividly illustrates the type of public and private injury which can result from an unreasonable delay in prosecuting patent claims. As a consequence, Lemelson’s asserted claims must be deemed unenforceable.”

While it is likely that the Lemelson Partnership will appeal this decision, if it is upheld then it will make it very difficult to enforce future submarine patents, especially where the delay in grant is directly due to the applicant.

This article was previously published as a regular X-Factor column in NZ BioScience, February 2004.