Patents Explained: Background and Field of Invention

Today in the Explaining Patents series: the background and field of invention section.

The background generally comprises two parts: an explanation of the field of invention and a description of the prior art.  The Patent Office rules suggest that it give context to the rest of the application, explain problems with the prior art, and describe objects of the invention.

This can be a tricky section.  Describing failures with the prior art can lead to the patent being construed narrowly – some courts will read the background and say, “well, if these were the problems in the prior art, your patent probably solves those problems and not others, because otherwise you would have described those other problems as well.”

For this reason and a few others, some patent attorneys do not believe in using a background section.  There really is nothing in the laws or rules that requires it, but leaving it out can risk initial complaints from the Patent Office, thus requiring back-and-forth discussion about whether it is really required.