A "Patent Cousin" is a patent that is related to another patent ("Starting Patent") not by direct citation but through common citation references.  There are two types of Patent Cousins:

• Backward Cousin:  This is a patent that cites one or more of the same patents that the Starting Patent cites
• Forward Cousin:  This is a patent that is cited by one or more patents that also cite the Starting Patent.

They are called "Backward Cousins" because to find them we begin with the Starting Set Patent(s)

Then we go "backward in time" to find patents (BC1 and BC2) cited by the Starting Patent(s).

Then we look for other patents (B-Cousins) that also cite backward to them:

This Backward Cousin Interconnection Map of U.S. 6359567 shows that patent (yellow star).

The green stars are the 6 patents (Backward Citation Patents) that are cited by U.S. 6359567.

The other "non-star" patents are the Backward Cousin Patents that also cite the green star Backward Citation Patents.

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They are called "Forward Cousins" because to find them we begin with the Starting Set Patent(s).

We then go "forward in time" to find patents (FC1 and FC2) that cite the Starting Patent(s).

Then we look for other patents (F-Cousins) that also cited by those "forward citation" patents:

This Forward Cousin Interconnection Map of U.S. 6685762 shows that patent (yellow star).

The "cyan stars" are the 5 patents (Forward Citation Patents) that cite U.S. 6359567 as prior patent art.

The other "non-star" patents are the Forward Cousin Patents that are also cited by the "cyan star" Forward Citation Patents.

Click on the map image to view a live version of the map