Simply, a declaration is an inventor’s promise – or acknowledgment of the promise – with the Patent Office. A patent application contains numerous pieces of information and paperwork. There is the patent disclosure itself, which includes the summary, background, description, drawings, and claims. The application likely also includes an information disclosure sheet, a power of attorney form, and an application data sheet. And lastly, the application will include a declaration.
The declaration is a short document that each inventor must sign asserting a few things. First, the inventor represents that he or she is the original inventor. In other words, he actually invented or contributed to at least one of the claims and did not take the idea from someone else. Second, the inventor acknowledges that he has read the contents of the application and understands them. Third, the inventor agrees to disclose to the Patent Office any information which may be material to the patentability of the invention. That is, if anything comes up during the prosecution of the patent application, the inventor has a duty to bring it the Patent Office’s attention. Failure to notify the Patent Office of relevant information is often a basis for having a patent invalidated down the line. This is a common defense raised by those accused of patent infringement: look for any prior art that should have been cited but wasn’t, and argue it was inequitable of the inventor or patent attorney to not have brought it up.