A validity search is made in conjunction with a client's current or potential litigation over a patent. It covers a wide range of prior art, similar to a patentability search. The purpose is to assess all prior art considered by the patent examiner prior to issuance of the patent and determine whether significant prior art documents and public information were overlooked. Any overlooked prior art may be sufficient to invalidate the patent if, had the examiner been aware of it, the patent would not have been issued. A patent which is invalid cannot be infringed.
Some searches look for prior patents about a specific technology or type of product or process.
Others look for patents issued to specific companies or inventors. Still others look for trends in technical developments. The searcher selected will have the appropriate technical expertise for the client's technology. Literature searches may be done wherever relevant publications are kept. For instance, in San Diego such locations include UCSD and SDSU libraries as well as the San Diego municipal and county library systems.