Patent Data Structure

Each record in the product describes a patent family. A patent family is a set of individual patents granted by various countries. There may be one or more patent numbers for each record and these represent the members of that patent family.

All specifications received by Derwent are checked to determine whether the inventions are new to Derwent. If the document relates to an entirely new invention, not previously seen by Derwent, then the document is designated as Basic and a new record is created.

If, however, the document covers the same invention as a Basic patent that has already been published in another country, and has been entered into the database, the document is designated as being Equivalent. The corresponding Basic record is updated with additional information from the Equivalent document. Together, the Basic and Equivalent patents form a patent family.


Patent Records

Records in the product show:

  • a patent family containing the master patents
  • a list of references that were cited by a master patent (Cited Patents)
  • later patents that cited the master patent in their references (Citing Patents)

The picture below shows the relationship between the master patent, its cited patents, and its citing patents.



Citations are captured for documents published by the six major patent-issuing authorities. A citation is a reference to an earlier patent.

Ongoing coverage is only provided for citations referenced by Patent Office Examiners, although backfile citation data is available for citations referenced by the inventor. Citations from both Basic and Equivalent documents are added to the patent family record. Both Basic and Equivalent members of the patent family can therefore act as the master patent for obtaining citation references. The references can be to patent or literature documents.