Since patents have to be applied for at a national rather than an international level, it means that a single invention is often associated with numerous identical patents around the world.
For this reason, the idea of a patent family was introduced so that patent analysts can rapidly identify patents that relate to a single invention around the world. (You can find more about patent families here: What Is A Patent Family?) This also prevents distortion within the analysis.
If for example, you want to monitor and compare innovation rates of companies in terms of how many single inventions they have patented, then counting patent families removes the bias of multiple worldwide patents describing the same invention. The INPADOC family grouping system is the world's most popular method for doing this, however, this system is not without its drawbacks. This is why PatSnap introduced its own Extended Patent Family methodology.
How is an Extended patent family built?
An extended patent family retrieves all the documents directly or indirectly linked to one specific priority document. They are built using a combination of the priority numbers and application numbers of the patents.
The patents are all linked by having at least one common priority belonging to the same patent family.
As a general rule, this includes national application numbers, international application numbers and domestic identifiers (e.g. divisional applications, continuations etc.). This also allows for additional connecting factors to be taken into account other than just the priority date, for example, patents with domestic application numbers.
What is the problem with INPADOC families?
We provide the INPADOC extended patent family grouping data within PatSnap, but we are aware that the INPADOC system has drawbacks. For example, not all of the patent numbers (i.e. priority number, application number) are normalized, which leads to some patents missing from families and being represented as individual patents with no family.
Why are our Extended families better?
We follow the same family rules as INPADOC, however, we provide a more powerful normalization of patent numbers, so that patents can be grouped into families correctly.
For example, if the priority number format from the New Zealand patent office adds a couple of zeroes in the middle of the number (NZ00123), but the Japanese patent office does not (JP123), we remove the zeroes so that the priority numbers match and the patents can be grouped.