Linking cited patents to inventors

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Joined: Thu Apr 17, 2014 2:02 pm

Linking cited patents to inventors

Post by LM2210 » Thu Apr 17, 2014 2:41 pm

Dear all,

I am currently working on my master thesis. In this context, I want to map the knowledge space of technologies in German regions based on patent citations data. In order to assign each cited patent to the location where it was invented, the “201401_EP_Citations” table needs to be matched with “201401_EPO_Inv_Reg” and “2014_PCT_Inv_Reg” tables.

In an existing post it is stated that supplementary tables can be matched by “(…) either Person_id, Appln_id, NPL_publn_id), so that it can be easily connected to PATSTAT April 2013.” ( ... ion#p10908).

In sum, “2014_EP_Citations” contains ~1 million citations of German patents (not unique patents). But when I try to link cited patents to their inventors, by using application IDs, application or publication numbers, only 300.000 patents can be matched. So 700.000 remain unmatched. It seems to me that application IDs, application and publication numbers are structured differently in all tables, as for example application IDs in “201401_EPO_Inv_Reg” are consecutive beginning at 1. This is not the case in “201401_EP_Citations” and “201401_PCT_Inv_Reg”, which exacerbates the matching procedure.
Furthermore, it looks like that all publication and application numbers are also of different kind in all three tables e.g. in terms of digits.

Is there an effective way to link all the three tables of interest? Why are the unique identifiers structured differently? Is there a big mistake in my matching procedure?

I really appreciate your help. Thank you very much in advance,

Posts: 140
Joined: Wed Jul 08, 2009 5:51 pm

Re: Linking cited patents to inventors

Post by nico.rasters » Fri Jul 11, 2014 7:42 pm

Sorry this post has remained unanswered for such a long time.

From the names of the tables in your post, I assume that you are trying to use the OECD Citations database, the OECD REGPAT database, and PATSTAT. You mention PATSTAT April 2013. Is that the version you are using?

I'm on October 2013, so the corresponding OECD Citations database would be January 2014 and the corresponding OECD REGPAT database is also from January 2014. For the April 2013 version of PATSTAT you'll be looking at the July 2013 for REGPAT... and I am guessing the Citations database will also be from July.

Let's start with EP_CITATIONS. This contains "patent applications filed to the EPO". So it does not cover the whole of PATSTAT. You want inventors, and you can get those through tls207_pers_appln if you add the criteria `invt_seq_nr`>0. However, the October version of PATSTAT introduced table tls227_pers_publn: "This table links each publication to its applicants and inventors. This can be used to analyse the changes of applicants / inventors at the times of their publication." But let's not complicate matters at this point.

tls207_pers_appln has an appln_id, and EP_CITATIONS has `Citing_appln_id` and `Cited_appln_id`. You mention "cited patents", so you should go for `Cited_appln_id`.

Btw, when you say "German patents", do you mean patents:
  • applied for in Germany
  • applied for by Germans
  • or invented by Germans?
"In order to assign each cited patent to the location where it was invented..." you can use the `Appln_id` field from the `EP_INV_REG` table in the OECD REGPAT database. That table is a list of EPO inventors... whatever an "EPO inventor" may be. Probably inventors of EPO patents because I see all sorts of country codes, not just European ones.

If you are still stuck on this, and if there is still time to save your Master thesis then feel free to send me an email at and I'll try to help you out.
Nico Doranov
Data Manager

Daigu Academic Services & Data Stewardship

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