The background is an extremely important section of a patent application. This section describes the state of the art in the particular technical area to which the patent relates and what problems remain to be solved or disadvantages accompanying the prior art solutions.
The use of background sections varies among the world’s patent regimes. In some patent systems the background section serves to disclose to the public the closest prior art applied against the patent application during examination. This is the situation in most European systems. In some countries such as the US, the prior art submitted by the patent applicant, as well as the prior art found by the examiner, is printed on the cover of the patent itself. Consequently, there is no need to list all or any of the cited references in the Background section.
The background section is typically considered prior art disclosed by the inventor. Consequently, if the applicant’s own inventive disclosure ends up in the background section, the patent examiner may cite this section in the rejection of the applicant’s claims. Some patent office takes a fairly hard line about inventive disclosures in background sections, which is one of the reasons why patent agents should draft them carefully.
It is sometimes advised that Background of the invention should describe what others have done in the field, and what problems have not been solved by this prior work. Generally, the related art should not be described in the Background section. Any description of the prior art should be limited to help identify the merits of the invention.
Many practitioners attempt to draft the shortest possible background sections out of fear that they will inadvertently and unintentionally deprive their client of the full scope of patent protection by saying too much about the prior art. A short background section might possibly not serve the public’s interest but it will not harm the client’s patent or foreclose the scope of the client’s possible claim protection.
To summarize, a good background section should be fairly short and merely set the stage for the technical disclosure to be provided in the detailed description section. The background section could describe the prior art at a very high level. The background section may conclude with a short, crisp statement about the shortcomings of the prior art but this must be written in a manner that does not disclose the solution to be described later in the application.