I want to filter for patents for a given industry. Although I see multiple fields with the name "category", none of them seem to be able to identify the related industry of a patent.
Is there a way to identify the industry that a patent comes from?
For example, I tried to retrieve the "cpc" fields (category, group_title, section_id) related to a bunch of patents, and all I get in return are NA's. Is this normal?
Btw, I am using R for this.
Thank you for your assistance