Hello,
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.
IPC / CPC historical coverage
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Re: IPC / CPC historical coverage
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
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