How To Read a Patent for Patent Searches

To conduct an effective patent search and also to understand the scope of a patent or rights conferred by a patent, it is important to understand what all information is available in a patent document and how to read a patent for patent searches.

A patent is a highly structured document and is divided into a number of fields. Important among which are:

    • Unique Identification Number of a Patent or a Published Patent Application
    • Consists of several parts:
      • Two Letter Country Code such as US, JP, EP etc. signifying where patent protection is sought or has been granted
      • Optionally any other letter(s) following the country code, indicating the kind of patent. E.g. in US, prefix USD signifies design patent, USRE signifies reissued patent
      • Numeric part, number of digits vary with country as well as kind of patent document – granted patent or application
      • Kind code, which is usually alphanumeric and denotes whether the document is an application or a granted patent, e.g. in US Patents – A1 denotes application while B2 denotes a granted patent.
  • TITLE: Few words or a sentence specifically relating to the invention
  • ABSTRACT: Brief summary of the invention as described and claimed as novel in the patent
  • PRIORITY, APPLICATION, PUBLICATION AND GRANT DATE: These dates are of great significance practically for all kind of patent searches
  • INVENTOR(s): All inventors of the patent would be mentioned
  • ASSIGNEE(s): If the patent/application has already been assigned, for example to a company – it would be listed here.
    • All patents are classified based on their technical fields using one or the other classification system
    • Some of the important systems are IPC, USPC etc.
    • There may be one or several classifications of each type.
  • REFERENCES/CITATIONS: These are the prior art related to the claimed invention identified either by the inventor or during examination of the patent application.
  • SPECIFICATION: This is usually the largest field of a patent document and describes-
    • Background and field of the invention so as to bring out the need for the invention and the problem which is to be solved
    • Existing or related solutions and their shortcomings
    • Brief Summary of the Invention stating the invention and how it solves the problem in the background
    • Detailed Description of the invention describing how the invention is to be carried out and its different forms
  • CLAIMS: Claims form the lifeline of a patent, patent provides protection only for the claimed invention. No matter what is disclosed in the specification, what is claimed is what is protected.


The knowledge of these patent fields is essential while doing patent searches and to formulate a patent search strategy best suited for your purpose. It would be great to randomly read a few patent documents to acquaint yourself with the pattern if not already done!

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