IPC / CPC historical coverage

Here you can post your opinions, ask questions and share experiences on the PATSTAT product line. Please always indicate the PATSTAT edition (e.g. 2015 Autumn Edition) and the database (e.g. PATSTAT Online, MySQL, MS SQL Server, ...) you are using.
Post Reply

Posts: 1
Joined: Thu Jun 13, 2019 3:40 pm

IPC / CPC historical coverage

Post by franperr » Thu Jun 13, 2019 3:46 pm

I am using PATSTAT 2016a to analyze patents using IPC and CPC codes since 1970.

I have a question and I could not find the answer in the data catalog nor on EPO website:

Since CPC was initiated in 2010 and IPC in 1975, how PATSTAT covers patents filled before 1975 ? Did you reclassify all the patents pre-1975, and for the CPC classification, you used a conversion table IPC -> CPC ?

Thank you.

Posts: 227
Joined: Thu Feb 22, 2007 5:33 pm

Re: IPC / CPC historical coverage

Post by EPO / PATSTAT Support » Tue Jul 09, 2019 7:53 am

Patents that were filed before the current classifications schemes came into existence, have been (re)classified using varying methods: human input, full text keyword analysis, concordance tables from existing classification schemes to new one’s or a combination of the different approaches.
There is no “one system fits all” to describe the current status of the data. Bottom line is that the examiners spend a large part of their time on so called “(re-)classification” work. This ensures that examiners can retrieve a reasonable amount of patents belonging to / covering the same technology.
In order not to miss-out on relevant prior art, also old patents have been / are classified using the latest classification schemes.
As a result of the above, you can find patent applications that have IPC codes printed on the document which are not been used in the original context anymore.
Here is a Dutch patent from 1926 that has IPC and CPC classification codes for “wind energy”: https://worldwide.espacenet.com/beta/se ... 3DNL19181C

ECLA to CPC was largely a simple re-naming of the scheme, with the exception that Y10S and Y10T were added to accommodate the US classification codes that were covered by ECLA.

I hope this answers your question.

PATSTAT Helpdesk

Post Reply