I want to do a patent search in a specific CPC class. How do I go about finding the most relevant patent documents from that class to quickly get an overview of the history of inventions in a specific field, without having to read at least 500 patent documents. Up until now I was sorting them by how often they got cited and even build myself a custom program (that costs me 1,00 € per search) for that, but I would like to find another way that is maybe even better.

  • There are many free patent search sites - why does a search cost ?
    – George White
    Feb 11 at 21:19
  • @GeorgeWhite You cannot search on those free patent search sites and order by number of times a patent document has been cited. I use Google BigQuery now for doing that and you have to pay there. Feb 12 at 9:12
  • You can, see my answer.
    – George White
    Feb 13 at 5:51

2 Answers 2


You should explore the things free tools can do for you. I went in to Lens (formally "The Lens" www.lens.org) and put in the search string "multiprocessor cache coherency".

The graphic displays included number of publications/patents over time, top assignees, top inventors and a bubble chart showing most cited.

enter image description here

Also, each hit shows the number of citations.

The data can be exported and one field you can chose to export is "cited by patent count". I searched on all patents in G06F12/082 and got 800+ hits. A screenshot of exported and sorted data is -

enter image description here


The EPO has a website for online search:


Also, I recommend you Open Patent Services (OPS) if you good at programming. More info at: https://www.epo.org/searching-for-patents/data/web-services/ops.html

It cost you if you use more than 4GB in a week.

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