What's the point of a patent search?
Patent searches may be performed for a number of purposes, but there are two primary types of searches that are requested by inventors and businesses for their developments.
The most common type of patent-related search is the patentability search, which is intended to provide a preliminary indication of whether an invention is likely to be approved for patenting by the U.S. Patent and Trademark Office if a patent application is filed.
Typically the search is limited to issued patents and published patent applications, but it can be extended to other types of publications and known products or processes as all of these things may be used as the basis to reject the claims of a patent application by a U.S.P.T.O. patent examiner. The results of this search may be used to form a preliminary opinion of the invention’s patentability. There is no legal requirement to have a patent search conducted before filing a patent application as patent examiners conduct their own searches of the prior art when examining a patent application.
Another type of patent-related search is a non-infringement or clearance search, which is not intended to determine if a development is patentable but instead whether the making, using, selling, importing, etc. of the development will infringe an unexpired patent. Generally this type of search is limited to patents that have issued in the most recent 20 year period, since that is approximately the longest possible term for a patent before it expires. After a patent expires, the invention covered by the patent is free to be used by anyone and that particular invention can never be patented again.