A patent is a set of exclusive rights given to creator/inventor to exclude others from making a duplicate copy of his/her findings viz. to exclude others from selling, making and using for limited time (usually 20 years). Patents can be granted in different countries, each having slightly different rules or legal formalities. Now if one wants to have legal protection over his invention in multiple countries, it would require him to file multiple patents for each country or region. It may cause duplication, to avoid this duplication, a concept of patent family was introduced to reduce multi-national results of one invention. Therefore, a group of patent documents that share same inventive concepts and technical details is known patent family. The basis of creation of patent families is the shared priority data so that all patent documents that are to be included in family are technically equivalent.

Patent Family

Comparative analysis of Different Patent Families:

Patent Table


Data Sources


  • International Patent Documentation Centre was founded in 1974 by an agreement between Austrian Patent Office and World Patent Organization. Its purpose is to collect and document patent families
  • A new family member must share at least one priority document with at least one other patent in the family. Therefore, a document’s INPADOC patent family means that it is an extended patent family
  • To reduce the re-classifying of older records, EPO worked on older documents without proper priority data, associating them using inventor and subject matter information to create artificial patent families
  • Due to their extensive family building rules INPADOC families can become quite large, chemical and biological subject fields tend to generate largest INPADOC families
  • The field of genetic engineering is known to have INPADOC patent families reaching thousands
  • The updating of INPADOC database mainly dependent on national patent office, which may not be able to provide regular updates. Another difficulty of relying on national patent office for the raw data is the quality of data. This leads to data error
  • This patent family data product is available to commercial patent information providers; it is the basis for many patent family databases

Derwent World Patents Index:

  • Uses human indexers to add abstract, indexing codes and re-written titles
  • Patents records are organized into intellectually created families, so that each family represents single subject invention
  • Creation relies on priority data
  • It is a simple patent family but systematically identifying non-convention equivalents which can make it as artificial patent family
  • DWPI database can never be current as all the new basic documents with unique priority data needs to be indexed before feeding them to database


  • Collection of records produced by Chemical Abstract Service (CAS) for the patent invention in chemical field
  • Contains re-written abstracts and human-indexed content
  • The new basic records are added to the database, but no additional indexing is done
  • Collection is an extended patent family


  • European Patent Organization’s Search Documentation System
  • This family structure formed the basis of PlusPat file
  • EPO’s internal patent examiner database
  • EDOC first consisted of application, priority and publication numbers. EPODOC then added abstracts, titles, inventors and applicants
  • In 1990 EPODOC was merged to INPADOC to serve internal database. Questel re-launched the commercial version of EDOC as PlusPat
  • It uses INPADOC as the source.


  • It is a simple patent family database
  • It is enhanced with key contents like: Object of invention, Advantages of the invention and drawbacks of the previous one and Independent claims
  • It includes EPO’s family rules along with the enhanced contents
  • It also includes: First page information, Classification nodes, Patent and non-patent literature citations, Full specifications, claims and detailed legal status information


  • It is precursor to FamPat database
  • It grouped all the publication stages of a patent at one place. It therefore prevents duplication
  • It is also known as the domestic patent family


  • It takes aggregated family data as the meta-record
  • Instead of indexing it focuses on loading full text data of an individual publication record to increase the chances of being found on search
  • It uses extended INPADOC patent family


  • Used to provide representative family members that constitute entire family record in English wherever possible
  • To search for equivalent records from other countries to match the technical content of the record undertaken
  • It is a simple patent family
  • EPO/DOCB is used as the database source

Comparative Analysis of Different Data Sources:

Comparative Analysis



Author: Mr. Ravi Shankar, Dr. Neeraj Maurya