The first section of a patent application is the “background” section. Many inventors write lengthy background sections which attempt to explain how the inventor came to invent the invention, how the invention is better that a number of existing inventions, and even some background on the inventor themselves. If I had to guess, this seems to be everyone’s favorite section to write. Everyone loves to tell their story.
In the recent case of Akeva LLC v Nike, Inc. (2020), the Background section of the patent in question describes the manner in which the current invention (a shoe with a movable/replaceable heel sole) differs from existing inventions (shoes with non-movable/non-replaceable heel soles). Later on, the inventor tried to argue that other improvements described in the application (compression resistant midsole) could be used in shoes with or without movable/replaceable heel soles. The court found that statements in the Background section helped to make it clear that a conventional fixed rear sole is not within the scope of the invention. Particularly, the Background section of the patent application in question said that “[t]o date, there is nothing in the art to address the combined problems of midsole compression and outsole wear in athletic shoes, and these problems remain especially severe in the heel area of such shoes.” The court found that by saying that existing inventions could not solve both of these problems, the inventor indicated that the current invention required both the movable/replaceable heel sole and the compression resistant midsole. For this reason, the wording in the Background section prevented the inventor from being able to get patent coverage for the compression resistant midsole in shoes with non-movable/non-replaceable heel soles.
The take away is that it is best and safest to keep the Background section very brief and to stay away from language that can be interpreted as describing the invention and what the invention must include. While it may help understanding of the invention to point out deficiencies in the prior art, it is important that the Background section does not include language that describes (i.e. limits) the invention to these deficiencies.
There is no benefit that we can see to writing a long and detailed Background section but there are plenty or risks. Moving forward I would even suggest limiting the Background section to just a few sentences very generally describing the problem your invention solves.