In patent_id 10216819, the assignee information is missing from the “g_assignee_disambiguated.tsv” file. On closer examination, I found that the assignee “International Business Machines Corporation” is listed as an applicant. I also found that the same is the case for patent_id 10003405. It is possible that there are many patents in the granted patent data for which the assignee information is missing because of the same reason. 

I read the article “The Case of the Missing Assignee Data: How the AIA Affected Pre-grant Assignee Information on Patent Applications” available on the PatentsView website. The article says that such discrepancies occur in the pre-grant data due to the change in the application process (2011 America Invents Act (AIA)) but did not affect the granted patent data. However, I found out that such discrepancies do exist in the granted patent data.

I want to know (1) how to find all the granted patents for which the assignee information is missing but the name of the assignee exists in the patent document (2) what I need to do so that I can include such patents in my data set with the correct assignee information.