Patent Research

Various types of patent research include a novelty search (also referred to as a patentability search), a collection search, a state-of-the-art search, an assignment search, a clearance search (also referred to as a freedom-to-operate search) and an invalidity search.

A novelty search is a search, typically for patents and patent publications, which are relevant to the novelty of an invention.  A novelty search provides a foundation enabling a patent attorney to develop a patentability opinion (see Patentability Opinion page), and gives the inventor some basis for deciding whether to proceed with a patent application.

A good novelty search should be conducted in the proper field of search, considering all patents and published applications in the most relevant patent classes and sub-classes, and independently including a keyword search based on a well thought-out keyword strategy.  Often, a patent Examiner in the relevant art at the USPTO is consulted to determine and/or confirm the field of search.  The USPTO provides a Seven Step Strategy for conducting a novelty search. 

A collection search is a search for all patents and published applications related to a particular form of technology.  This type of search could result in a relatively large number of patents and published applications, depending on the search parameters.  It may be limited by assignee, classification, keywords, or some period of time

A state-of-the-art search, like a collection search, is a search for patents and published applications related to a particular technology.  The search is generally limited to produce patents and applications that have granted or published in more recent years, such as over the past 10-15 years.  In a state-of-the-art search, the searcher uses discretion in selecting patents and applications that are most representative of the current state of the art.

An assignment search is a search for patents and published applications assigned to an assignee.  It is commonly used to find a competitor’s patents and publications, to learn what technology that a competitor has patented and is patenting.  US patents grant every Tuesday and US patent applications publish every Thursday.  Conducting an assignment search once a week can capture a competitor’s patents and published applications that grant or publish during that week.  This is referred to as a “patent watch.”  Patent watch services are typically provided for a modest monthly or annual fee.

A clearance search is a search for all patents and published applications related to a product, often during its development or prior to its launch.  Every patent and published application in every relevant class and sub-class (i.e., the field of search) must be considered.  A keyword search may aid in capturing relevant patents and published applications that are in a less relevant field of search.  Clearance searches can be very expansive and thus costly.  However, they provide a useful basis for a clearance opinion (see Clearance Opinion page). 

An invalidity search is a search for “prior art,” which includes patents or published applications that predate a patent that may be infringed.  It provides a basis for invalidating the patent claims.  To avoid infringement of a patent, every claim in the patent has to be either invalid or clear of infringement.  In order for a claim to be invalid, all the limitations of the claim have to be disclosed in the prior art.  A single prior art reference is one that shows all the claim limitations.  This is referred to as an “anticipatory reference” because it anticipates a claim.  A claim may also be invalid in view of a combination of prior art references if it would have been obvious to one of ordinary skill in the art to combine the references to arrive at the claimed invention. 

Each patent cites other patents or publications considered by the patent Examiner during the examination of the patents.  A forward citation search is a search for the patents and published applications that cite a particular patent.  A rearward citation search is a search for the patents and published applications that are cited by the particular patent.  In theory, patents typically cite other patents and published applications that are commonly relevant (i.e., relevant to one another).  Citation searching is generally useful when trying to find patents or publications that are better than the one in hand.  The USPTO Patent Search Database and Patent Application Search Database are great tools for conducting forward and rearward citation searches.

Searches for US patents and patent publications may be conducted using free internet based tools, such as the USPTO Patent Search Databases, Google Patents, Free Patents Online, and searches for foreign patents and patent publications may be conducted using similar tools, such as the EPO Patent Search Database (i.e., the INPADOC system) and the WIPO Patent Search Database at the World Intellectual Property Organization (WIPO)). 

Internet based search tools and services, such as Delphion, Thomson Reuters and TotalPatent (the latter being available through LexisNexis) are also available on a commercial or subscription basis. 

Searches are often outsourced to patent research services, including public searchers or search firms.  Research services often conduct searches using the Examiner Automated Search Tool (referred to as the EAST system) or the Web-based Examiner Search Tool (referred to as the WEST System) at the USPTO.  They should be familiar with the US Patent Classification (USPC) system, and can consult Examiners at the USPTO to establish an appropriate field of search.

Research services should provide search reports that clearly describe the subject matter being searched, indicate the field of search, the keyword search strategy and Examiners consulted, and describe the relevance of the references (i.e., why each reference is cited). 

The cost of a novelty search for a simple mechanical invention is generally in the range of $350 USD to $1500 USD

Collection, state-of-the-art, assignment, clearance and invalidity searches all vary in cost according to search parameters and the complexity of the search. 

If you have a question about patent research, askme at